View MAX8671X_4099898.PDF datasheet online --- IC-ON-LINE

Datasheet File OCR Text:

19-0885; Rev 0; 8/07
KIT ATION EVALU BLE AVAILA
PMIC with Integrated Charger and Smart Power Selector for Handheld Devices
General Description Features
o 16V-Tolerant USB and DC Inputs o Automatically Powers from External Power or Battery o Operates with No Battery Present o Single-Cell Li+/Li-Poly Charger o Three 2MHz Step-Down Regulators Up to 96% Efficiency o Two Low IQ Linear Regulators o Output Power-Up Sequencing o Thermal-Overload Protection
MAX8671X
The MAX8671X integrated power-management IC (PMIC) is ideal for use in portable media players and other handheld devices. In addition to five regulated output voltages, the MAX8671X integrates a 1-cell lithium ion (Li+) or lithium polymer (Li-Poly) charger and Smart Power SelectorTM with dual (AC-to-DC adapter and USB) power inputs*. The dual-input Smart Power Selector supports end products with dual or single power connectors. All power switches for charging and switching the system load between battery and external power are included on-chip. No external MOSFETs are required. Maxim's Smart Power Selector makes the best use of limited USB or AC-to-DC adapter power. Battery charge current and input current limit are independently set. Input power not used by the system charges the battery. Charge current and DC current limit are programmable up to 1A while USB input current can be set to 100mA or 500mA. Automatic input selection switches the system load from battery to external power. Other features include overvoltage protection, charge status and fault outputs, power-OK monitors, charge timer, and battery thermistor monitor. In addition, on-chip thermal limiting reduces battery charge rate to prevent charger overheating. The MAX8671X offers adjustable voltages for all outputs. Similar parts with factory-preset output voltages are also available (contact factory for availability).
Ordering Information
PART TEMP RANGE PIN-PACKAGE 40 Thin QFN-EP* 5mm x 5mm PKG CODE T4055-1
MAX8671XETL+ -40C to +85C
+Denotes a lead-free package. *EP = Exposed paddle.
Simplified Applications Circuit
MAX8671X
Applications
Portable Audio Players GPS Portable Navigators
AC-TO-DC ADAPTER
DC
SYS
USB ON OFF
USB + EN PWM OUT1 OUT1 1V TO VSYS 425mA OUT2 1V TO VSYS 425mA OUT3 1V TO VSYS 425mA Li+/LiPo BATTERY
PEN1 PEN2 USUS CEN P CST1 CST2 DOK
OUT2
OUT3
OUT4
OUT4 0.6V TO VSYS 180mA OUT5 0.6V TO VSYS 180mA
*Protected by US Patent #6,507,172.
UOK OUT5
Smart Power Selector is a trademark of Maxim Integrated Products, Inc.
________________________________________________________________ Maxim Integrated Products 1
For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642, or visit Maxim's website at www.maxim-ic.com.
PMIC with Integrated Charger and Smart Power Selector for Handheld Devices MAX8671X
Table of Contents
General Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 Applications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 Ordering Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 Simplified Applications Circuit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 Table of Contents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 Absolute Maximum Ratings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 Electrical Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 Typical Operating Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 Pin Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 Detailed Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24 SMART POWER SELECTOR . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24 System Load Switch . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 USB Power Input (USB) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 USB Power-OK Output (UOK) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26 USB Suspend (USUS) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26 DC Power Input (DC) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26 DC Power-OK Output (DOK) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27 BATTERY CHARGER . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28 BATTERY REGULATION VOLTAGE (BVSET) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28 CHARGE ENABLE INPUT (CEN) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28 CHARGE STATUS OUTPUTS (CST1, CST2) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30 CHARGE TIMER (CT) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31 SETTING THE CHARGER CURRENTS (CISET) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .31 STEP-DOWN CONVERTERS (REG1, REG2, REG3) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32 PWM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33 Step-Down Dropout and Minimum Duty Cycle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33 Step-Down Input Capacitors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33 Step-Down Output Capacitors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33 Step-Down Inductor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34 Step-Down Converter Output Current . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .34 LINEAR REGULATORS (REG4, REG5) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35 VL LINEAR REGULATOR . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35 ENABLE/DISABLE (EN) AND SEQUENCING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36 SOFT-START/INRUSH CURRENT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37 ACTIVE DISCHARGE IN SHUTDOWN . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38 UNDERVOLTAGE AND OVERVOLTAGE LOCKOUT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38 USB/DC UVLO . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38 USB/DC OVLO . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39 SYS UVLO . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39 REG4/REG5 UVLO . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .39 THERMAL LIMITING AND OVERLOAD PROTECTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39 Smart Power Selector Thermal-Overload Protection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .39 Regulator Thermal-Overload Shutdown . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39 Battery Charger Thermistor Input (THM) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39 PCB LAYOUT AND ROUTING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41 PACKAGE MARKING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .41 Chip Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41 Pin Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42 Package Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43
2
_______________________________________________________________________________________
PMIC with Integrated Charger and Smart Power Selector for Handheld Devices
Table of Contents (continued)
Tables Table 1. Input Limiter Control Logic . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24 Table 2. DC Current Limit for Standard Values of RDISET . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27 Table 3. Charge Status Outputs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31 Table 4. Charge Times vs. CCT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31 Table 5. Ideal Charge Currents vs. Charge Setting Resistor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32 Table 6. Suggested Inductors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34 Table 7. 5mm x 5mm x 0.8mm Thin QFN Thermal Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39 Table 8. Trip Temperatures for Different Thermistors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40 Figures Figure 1. MAX8671X Typical Application Circuit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22 Figure 2. Functional Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23 Figure 3. USB Power-OK Logic . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26 Figure 4. Programming DC Current Limit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27 Figure 5. DC Power-OK Logic . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28 Figure 6. Li+/Li-Poly Charge Profile . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29 Figure 7. Charger State Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30 Figure 8. Programming Charge Current . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31 Figure 9. Monitoring the Battery Charge Current with the Voltage from CISET to AGND . . . . . . . . . . . . . . . . . . 32 Figure 10. Step-Down Converter Maximum Output Current Example . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35 Figure 11. Enable/Disable Logic . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36 Figure 12. Enable and Disable Waveforms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37 Figure 13. REG5 Disable Detail . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38 Figure 14. Thermistor Input . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40 Figure 15. Package Marking Example . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41
MAX8671X
_______________________________________________________________________________________
3
PMIC with Integrated Charger and Smart Power Selector for Handheld Devices MAX8671X
ABSOLUTE MAXIMUM RATINGS
USB, DC, PEN1 to AGND.......................................-0.3V to +16V SYS, BAT, PV1, PV2, PV3 to AGND..........................-0.3V to +6V PG1, PG2, PG3, AGND .........................................-0.3V to +0.3V PV1, PV2, PV3 to SYS............................................-0.3V to +0.3V VL to AGND ...........................................................-0.3V to +4.0V CISET, DISET, BVSET, CT, THM to AGND..-0.3V to (VVL + 0.3V) PV4, PV5, BP, FB1, FB2, FB3 to AGND ....-0.3V to (VSYS + 0.3V) PEN2, USUS, CEN, EN, PWM to AGND ..................-0.3V to +6V CST1, CST2, DOK, UOK to AGND ...........................-0.3V to +6V OUT4, FB4 to AGND .................................-0.3V to (VPV4 + 0.3V) OUT5, FB5 to AGND .................................-0.3V to (VPV5 + 0.3V) LX1, LX2, LX3 Continuous RMS Current (Note 1).................1.5A BAT Continuous Current .......................................................1.5A SYS Continuous Current .......................................................1.5A Continuous Power Dissipation (TA = +70C) 40-Pin, 5mm x 5mm, Thin QFN (derate 35.7mW/C above +70C)..............................................................2857mW Operating Junction Temperature.....................................+150C Storage Junction Temperature Range ..............-65C to +150C Lead Temperature (soldering, 10s) .................................+300C
Note 1: LX_ has internal clamp diodes to PG_ and PV_. Applications that forward bias these diodes must take care not to exceed the package power dissipation limits.
Stresses beyond those listed under "Absolute Maximum Ratings" may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability.
ELECTRICAL CHARACTERISTICS
(DC, USB, BVSET, UOK, DOK, LX_ unconnected; VTHM = VL/2, VPG_ = VAGND = 0V, VBAT = 4V, CEN = low, USUS = low, EN = high, VPEN1 = VPEN2 = 3.3V, VPWM = 0V, COUT4 = 1F, COUT5 = 1F, CSYS = 10F, PV1 = PV2 = PV3 = PV4 = PV5 = SYS, RDISET = 3k, RCISET = 3k, CVL = 0.1F, CCT = 0.15F, CBP = 0.01F, VFB1 = 1.1V, VFB2 = 1.1V, VFB3 = 1.1V, TA = -40C to +85C, unless otherwise noted.) (Note 2)
PARAMETER SYMBOL CONDITIONS Operating voltage Withstand voltage VDC = 6V, USUS = low, CEN = high, system current is less than the input current limit VDC rising, 500mV typical hysteresis VDC rising, 400mV typical hysteresis PEN1 = low, VDC = 6V, VSYS = 5V PEN2 = low, USUS = low USB unconnected, CEN = low, PEN1 = low, TA = +25C, PEN2 = high, VL = no load USUS = low (Note 3) PEN1 = high, RDISET = 3k PEN1 = low, USUS = high USUS = low, CEN = low; ISYS = 0mA, IBAT = 0mA, EN = low; VL no load USUS = low, CEN = high; ISYS = 0mA, VEN = 0V, VL no load Minimum DC-to-BAT Voltage Headroom Minimum DC-to-SYS Voltage Headroom DC-to-SYS Dropout Resistance RDS VDC falling, 200mV hysteresis VDC falling, 200mV hysteresis VDC = 5V, ISYS = 400mA, USUS = low 0 0 MIN 4.1 0 5.2 3.95 6.8 90 5.3 4.00 6.9 95 TYP MAX 6.6 14 5.4 4.05 7.0 100 mA UNITS DC POWER INPUT (VDC = 5.0V, EN = low) DC Voltage Range SYS Regulation Voltage DC Undervoltage Threshold DC Overvoltage Threshold VDC VSYS_REG VDCL VDCH V V V V
DC Current Limit
IDCLIM
450 950 3
475 1000
500 1050 6
RDISET Resistance Range
k
0.11 1.1
DC Quiescent Current
IDCIQ
mA
0.7 15 15 0.325 30 30 0.600 mV mV
4
_______________________________________________________________________________________
PMIC with Integrated Charger and Smart Power Selector for Handheld Devices
ELECTRICAL CHARACTERISTICS (continued)
(DC, USB, BVSET, UOK, DOK, LX_ unconnected; VTHM = VL/2, VPG_ = VAGND = 0V, VBAT = 4V, CEN = low, USUS = low, EN = high, VPEN1 = VPEN2 = 3.3V, VPWM = 0V, COUT4 = 1F, COUT5 = 1F, CSYS = 10F, PV1 = PV2 = PV3 = PV4 = PV5 = SYS, RDISET = 3k, RCISET = 3k, CVL = 0.1F, CCT = 0.15F, CBP = 0.01F, VFB1 = 1.1V, VFB2 = 1.1V, VFB3 = 1.1V, TA = -40C to +85C, unless otherwise noted.) (Note 2)
PARAMETER DC-to-SYS Soft-Start Time DC Thermal-Limit Temperature DC Thermal-Limit Gain USB POWER INPUT (VUSB = 5.0V, EN = low) USB Voltage Range VUSB Operating voltage Withstand voltage VUSB = 6V, USUS = low, CEN = high, system current is less than the input current limit VUSB rising, 500mV hysteresis VUSB rising, 400mV hysteresis VUSB = 6V, VSYS = 5V, DC unconnected, CEN = low, TA = +25C, IVL = 0A (Note 3) USUS = high USB Quiescent Current IUSBIQ USUS = low, CEN = low; ISYS = 0mA, IBAT = 0mA, VL no load USUS = low, CEN = high; ISYS = 0mA, VL no load Minimum USB-to-BAT Voltage Headroom Minimum USB-to-SYS Voltage Headroom USB-to-SYS Dropout Resistance USB-to-SYS Soft-Start Time USB Thermal-Limit Temperature USB Thermal-Limit Gain SYSTEM (VDC = 5.0V, EN = low) System Operating Voltage Range System Undervoltage Threshold VSYS VUVLO_SYS SYS falling, 100mV hysteresis 2.6 2.45 2.50 5.5 2.55 V V RUS tSS-U-S Die temperature at which current limit is reduced Amount of input current reduction above thermal-limit temperature VUSB falling, 200mV hysteresis VUSB falling, 200mV hysteresis VUSB = 5V, ISYS = 400mA, USUS = low 0 0 PEN2 = low, USUS = low PEN2 = high, USUS = low 4.1 0 5.2 3.95 6.8 90 450 5.3 4.0 6.9 95 475 0.11 1.1 0.7 15 15 0.325 1.0 100 5 2.0 1.3 30 30 0.600 mV mV ms C %/C mA 6.6 14 5.4 4.05 7.0 100 mA 500 V SYMBOL tSS-D-S CONDITIONS Starting DC when no USB present Starting DC with USB present Die temperature at which current limit is reduced Amount of input current reduction above thermal-limit temperature MIN TYP 1.0 35 +100 5 MAX UNITS ms s C %/C
MAX8671X
SYS Regulation Voltage USB Undervoltage Threshold USB Overvoltage Threshold
VSYS_REG VUSBL VUSBH
V V V
USB Current Limit
IUSBLIM
_______________________________________________________________________________________
5
PMIC with Integrated Charger and Smart Power Selector for Handheld Devices MAX8671X
ELECTRICAL CHARACTERISTICS (continued)
(DC, USB, BVSET, UOK, DOK, LX_ unconnected; VTHM = VL/2, VPG_ = VAGND = 0V, VBAT = 4V, CEN = low, USUS = low, EN = high, VPEN1 = VPEN2 = 3.3V, VPWM = 0V, COUT4 = 1F, COUT5 = 1F, CSYS = 10F, PV1 = PV2 = PV3 = PV4 = PV5 = SYS, RDISET = 3k, RCISET = 3k, CVL = 0.1F, CCT = 0.15F, CBP = 0.01F, VFB1 = 1.1V, VFB2 = 1.1V, VFB3 = 1.1V, TA = -40C to +85C, unless otherwise noted.) (Note 2)
PARAMETER BAT-to-SYS Reverse Regulation Voltage SYMBOL CONDITIONS DC or USB and BAT are sourcing current BAT is sourcing 105mA BAT is sourcing 905mA MIN 65 TYP 82 130 0 0 10 10 MAX 115 mV UNITS
VBSREG
DC and USB unconnected, EN = low, VBAT = 4V VDC = VUSB = 5V, USUS = high, PEN1 = low, EN = low, VBAT = 4V IPV1 + IPV2 + IPV3 + IPV4 + IPV5 + ISYS DC and USB unconnected, EN = high, VBAT = 4V (step-down converters are not in dropout), PWM = low (Note 4) DC and USB unconnected, EN = high, VBAT = 2.8V (at least one step-down converter is in dropout), PWM = low (Note 4) VDC = VUSB = 5V, USUS = high, EN = high, VBAT = 4V, PWM = low (Note 4) DC and USB unconnected, EN = high, VBAT = 4.0V, PWM = high BATTERY CHARGER (VDC = 5.0V, EN = low) BAT-to-SYS On-Resistance RBS VUSB = 0V, VBAT = 4.2V, ISYS = 1A BVSET = VL or BVSET unconnected BAT Regulation Voltage (Figure 6) VBATREG BVSET = AGND RBVSET = 49.9k to AGND BAT Recharge Threshold BAT Prequalification Threshold RCISET Resistance Range CISET Voltage VCISET VBATRCHG (Note 5) VBATPRQ VBAT rising, 180mV hysteresis, Figure 6 Guaranteed by BAT fast-charge current limit RCISET = 7.5k, IBAT = 267mA, Figure 9 TA = +25C TA = -40C to +85C TA = +25C TA = -40C to +85C TA = +25C TA = -40C to +85C 4.174 4.145 4.073 4.047 4.325 4.297 -170 2.9 3 0.9
155
285
A
Quiescent Current
425
550
180 9
320 mA
0.08 4.200 4.200 4.100 4.100 4.350 4.350 -120 3.0
0.16 4.221 4.242 4.121 4.141 4.376 4.398 -70 3.1 15
V
mV V k V
1.0
1.1
6
_______________________________________________________________________________________
PMIC with Integrated Charger and Smart Power Selector for Handheld Devices
ELECTRICAL CHARACTERISTICS (continued)
(DC, USB, BVSET, UOK, DOK, LX_ unconnected; VTHM = VL/2, VPG_ = VAGND = 0V, VBAT = 4V, CEN = low, USUS = low, EN = high, VPEN1 = VPEN2 = 3.3V, VPWM = 0V, COUT4 = 1F, COUT5 = 1F, CSYS = 10F, PV1 = PV2 = PV3 = PV4 = PV5 = SYS, RDISET = 3k, RCISET = 3k, CVL = 0.1F, CCT = 0.15F, CBP = 0.01F, VFB1 = 1.1V, VFB2 = 1.1V, VFB3 = 1.1V, TA = -40C to +85C, unless otherwise noted.) (Note 2)
PARAMETER SYMBOL CONDITIONS Low-power USB charging from the USB input, DC unconnected, RCISET = 3k, PEN2 = low, USUS = low Low-power USB charging from the DC input, RCISET = 3k, PEN1 = low, PEN2 = low, USUS = low High-power USB charging from the USB input, DC unconnected, RCISET = 3k, PEN2 = high, USUS = low High-power USB charging from the DC input, RCISET = 3k, PEN2 = high, USUS = low AC-to-DC adapter charging from the DC input, RDISET = 3k, RCISET = 15k, PEN1 = high AC-to-DC adapter charging from the DC input, RDISET = 3k, RCISET = 7.5k, PEN1 = high AC-to-DC adapter charging from the DC input, RDISET = 3k, RCISET = 3.74k, PEN1 = high VBAT = 2.5V, RCISET = 3.74k TA = +25C, RCISET = 3.74k (Note 6) No DC or USB power connected DC and/or USB power connected, CEN = high -5 MIN 87 TYP 92 MAX 100 UNITS
MAX8671X
87
92
100
450
472
500
BAT Fast-Charge Current Limit
450
472
500
mA
170
200
230
375
400
425
750 65 20
802 82 30 0 1 450 1.10 0.22 0.88
850 100 40 +5 A +5 mA/ms ms +20 % mV mA mA
BAT Prequalification Current Top-Off Threshold
BAT Leakage Current
EN = low, TA = +25C Slew rate
Charger Soft-Start Time
tSS_CHG
Time from 0mA to 500mA Time from 0mA to 100mA Time from 100mA to 500mA CCT = 0.15F CISET voltage when the fast-charge timer suspends; 300mV translates to 20% of the maximum fast-charge current limit CISET voltage when the fast-charge timer suspends; 750mV translates to 50% of the maximum fast-charge current limit -20 250
Timer Accuracy Timer Suspend Threshold
300
350
Timer Extend Threshold
700
750
800
mV
_______________________________________________________________________________________
7
PMIC with Integrated Charger and Smart Power Selector for Handheld Devices MAX8671X
ELECTRICAL CHARACTERISTICS (continued)
(DC, USB, BVSET, UOK, DOK, LX_ unconnected; VTHM = VL/2, VPG_ = VAGND = 0V, VBAT = 4V, CEN = low, USUS = low, EN = high, VPEN1 = VPEN2 = 3.3V, VPWM = 0V, COUT4 = 1F, COUT5 = 1F, CSYS = 10F, PV1 = PV2 = PV3 = PV4 = PV5 = SYS, RDISET = 3k, RCISET = 3k, CVL = 0.1F, CCT = 0.15F, CBP = 0.01F, VFB1 = 1.1V, VFB2 = 1.1V, VFB3 = 1.1V, TA = -40C to +85C, unless otherwise noted.) (Note 2)
PARAMETER Prequalification Time Fast-Charge Time Top-Off Time SYMBOL tPQ tFC tTO CCT = 0.15F CCT = 0.15F CONDITIONS MIN TYP 33 660 15 MAX UNITS min min s % of VVL % of VVL A
THERMISTOR INPUT (THM) (VDC = 5.0V, EN = low) THM Threshold, Cold THM Threshold, Hot THM Input Leakage Current VTHMC VTHMH ITHM VTHM rising, 65mV hysteresis VTHM falling, 65mV hysteresis THM = AGND or VL, TA = +25C THM = AGND or VL, TA = +85C 73.0 27.0 -0.100 74.0 28.4 0.001 0.01 120 2.6 0.4 2.6 2.6 0.3 3.0 3.0 TJ rising +165 15 PV1 supplied from SYS L = 4.7H, RL = 0.13 (Note 7) (Note 8) TA = +25C TA = +85C 425 0.997 1 VFB1 = 1.012V PWM mode PWM mode (Note 9) VPV1 = 4V, ILX1 = 180mA VPV1 = 4V, ILX1 = 180mA 0.555 -50 -5 -5 4.4 1 165 200 0.615 330 400 0.675 1.012 1.028 VSYS +50 VSYS 75.5 30.0 +0.200
POWER SEQUENCING (Figures 11 and 12) EN to REG3 Enable Delay REG1 Soft-Start Time REG3 to REG1/2 Delay REG2 Soft-Start Time REG3 Soft-Start Time REG1/2 to REG4 Delay REG4 Soft-Start Time REG5 Soft-Start Time REGULATOR THERMAL SHUTDOWN Thermal Shutdown Temperature Thermal Shutdown Hysteresis REG1--SYNCHRONOUS STEP-DOWN CONVERTER Input Voltage Maximum Output Current FB1 Voltage Adjustable Output Voltage Range FB1 Leakage Current Load Regulation Line Regulation p-Channel On-Resistance n-Channel On-Resistance p-Channel Current-Limit Threshold V mA V V nA %/A %/D m m A C C tD1 tSS1 tD2 tSS2 tSS3 tD3 tSS4 tSS5 s ms ms ms ms ms ms ms
8
_______________________________________________________________________________________
PMIC with Integrated Charger and Smart Power Selector for Handheld Devices
ELECTRICAL CHARACTERISTICS (continued)
(DC, USB, BVSET, UOK, DOK, LX_ unconnected; VTHM = VL/2, VPG_ = VAGND = 0V, VBAT = 4V, CEN = low, USUS = low, EN = high, VPEN1 = VPEN2 = 3.3V, VPWM = 0V, COUT4 = 1F, COUT5 = 1F, CSYS = 10F, PV1 = PV2 = PV3 = PV4 = PV5 = SYS, RDISET = 3k, RCISET = 3k, CVL = 0.1F, CCT = 0.15F, CBP = 0.01F, VFB1 = 1.1V, VFB2 = 1.1V, VFB3 = 1.1V, TA = -40C to +85C, unless otherwise noted.) (Note 2)
PARAMETER Skip Mode Transition Current n-Channel Zero-Crossing Threshold Maximum Duty Cycle Minimum Duty Cycle Internal Oscillator Frequency Internal Discharge Resistance in Shutdown Input Voltage Maximum Output Current FB2 Voltage Adjustable Output Voltage Range FB2 Leakage Current Load Regulation Line Regulation p-Channel On-Resistance n-Channel On-Resistance p-Channel Current-Limit Threshold Skip Mode Transition Current n-Channel Zero-Crossing Threshold Maximum Duty Cycle Minimum Duty Cycle Internal Oscillator Frequency Internal Discharge Resistance in Shutdown Input Voltage Maximum Output Current FB3 Voltage Adjustable Output Voltage Range FB3 Leakage Current Load Regulation VFB2 = 1.012V PWM mode TA = +25C TA = +85C EN = low, resistance from LX2 to PG2 PWM mode 1.8 0.5 (Note 10) VFB2 = 1.012V PWM mode PWM mode (Note 9) VPV2 = 4V, ILX2 = 180mA VPV2 = 4V, ILX2 = 180mA 0.555 TA = +25C TA = +85C EN = low, resistance from LX1 to PG1 PWM mode 1.8 0.5 SYMBOL (Note 10) CONDITIONS MIN TYP 60 10 100 12.5 2.0 1.0 2.2 2.0 MAX UNITS mA mA % % MHz k
MAX8671X
REG2--SYNCHRONOUS STEP-DOWN CONVERTER PV2 supplied from SYS L = 4.7H, RL = 0.13 (Note 7) (Note 8) 425 0.997 1 -50 -5 -50 4.4 1 200 150 0.615 60 10 100 12.5 2.0 1.0 2.2 2.0 400 265 0.675 1.012 1.028 VSYS +50 VSYS V mA V V nA %/A %/D m m A mA mA % % MHz k
REG3--SYNCHRONOUS STEP-DOWN CONVERTER PV3 supplied from SYS L = 4.7H, RL = 0.13 (Note 7) (Note 8) 425 0.997 1 -50 -5 -50 4.4 1.012 1.028 VSYS +50 VSYS V mA V V nA %/A
_______________________________________________________________________________________
9
PMIC with Integrated Charger and Smart Power Selector for Handheld Devices MAX8671X
ELECTRICAL CHARACTERISTICS (continued)
(DC, USB, BVSET, UOK, DOK, LX_ unconnected; VTHM = VL/2, VPG_ = VAGND = 0V, VBAT = 4V, CEN = low, USUS = low, EN = high, VPEN1 = VPEN2 = 3.3V, VPWM = 0V, COUT4 = 1F, COUT5 = 1F, CSYS = 10F, PV1 = PV2 = PV3 = PV4 = PV5 = SYS, RDISET = 3k, RCISET = 3k, CVL = 0.1F, CCT = 0.15F, CBP = 0.01F, VFB1 = 1.1V, VFB2 = 1.1V, VFB3 = 1.1V, TA = -40C to +85C, unless otherwise noted.) (Note 2)
PARAMETER Line Regulation p-Channel Current-Limit Threshold Skip Mode Transition Current n-Channel Zero-Crossing Threshold p-Channel On-Resistance n-Channel On-Resistance Maximum Duty Cycle Minimum Duty Cycle Internal Oscillator Frequency Internal Discharge Resistance in Shutdown REG4--LINEAR REGULATOR PV4 Operating Range PV4 Undervoltage Lockout Threshold FB4 Voltage FB4 Leakage Current Drop-Out Resistance Current Limit VPV4 VPV4 rising, 100mV hysteresis No load VFB4 = 0.6V TA = +25C TA = +85C 1.7 1.55 0.582 -50 1.60 0.600 -5 -5 0.45 0.75 200 230 235 120 1.8 265 VSYS 1.65 0.618 +50 V V V nA mA EN = low, resistance from LX3 to PG3 PWM mode 1.8 0.5 VPV3 = 4V, ILX3 = 180mA VPV3 = 4V, ILX3 = 180mA (Note 10) SYMBOL CONDITIONS PWM mode (Note 9) 0.555 MIN TYP 1 0.615 60 10 230 120 100 12.5 2.0 1.0 2.2 2.0 460 210 0.675 MAX UNITS %/D A mA mA m m % % MHz k
PV4 to OUT4, VPV4 = 3.3V PV4 to OUT4, VPV4 = 2.0V VFB4 = 0.54V VFB4 = 0V 10Hz to 100kHz; COUT4 = 3.3F, IOUT4 = 10mA, VPV4 = 2V, VOUT4 set for 1.8V f = 1kHz, IOUT4 = 10mA, VPV4 = 2V, VOUT4 set for 1.8V f = 10kHz, IOUT4 = 10mA, VPV4 = 2V, VOUT4 set for 1.8V
Output Noise
VRMS
67 dB 50 0.5 1.0 2.0 k
PSRR
Internal Discharge Resistance in Shutdown
EN = low, resistance from OUT4 to AGND
10
______________________________________________________________________________________
PMIC with Integrated Charger and Smart Power Selector for Handheld Devices
ELECTRICAL CHARACTERISTICS (continued)
(DC, USB, BVSET, UOK, DOK, LX_ unconnected; VTHM = VL/2, VPG_ = VAGND = 0V, VBAT = 4V, CEN = low, USUS = low, EN = high, VPEN1 = VPEN2 = 3.3V, VPWM = 0V, COUT4 = 1F, COUT5 = 1F, CSYS = 10F, PV1 = PV2 = PV3 = PV4 = PV5 = SYS, RDISET = 3k, RCISET = 3k, CVL = 0.1F, CCT = 0.15F, CBP = 0.01F, VFB1 = 1.1V, VFB2 = 1.1V, VFB3 = 1.1V, TA = -40C to +85C, unless otherwise noted.) (Note 2)
PARAMETER REG5--LINEAR REGULATOR PV5 Operating Range PV5 Undervoltage Lockout Threshold FB5 Voltage FB5 Leakage Current Drop-Out Resistance Current Limit VPV5 VPV5 rising, 100mV hysteresis No load VFB5 = 0.6V TA = +25C TA = +85C 1.7 1.55 0.582 -50 1.60 0.600 -5 -5 0.45 0.75 200 230 235 180 1.8 265 VSYS 1.65 0.618 +50 V V V nA mA SYMBOL CONDITIONS MIN TYP MAX UNITS
MAX8671X
VPV5 to OUT5, VPV5 = 3.3V VPV5 to OUT5, VPV5 = 2.0V VFB5 = 0.54V VFB5 = 0V 10Hz to 100kHz, COUT5 = 2.2F, IOUT5 = 10mA, VPV5 = 3.5V, VOUT5 set for 3.3V f = 1kHz, IOUT5 = 10mA, VPV5 = 3.5V, VOUT5 set for 3.3V f = 10kHz, IOUT5 = 10mA, VPV5 = 3.5V, VOUT5 set for 3.3V EN = low, resistance from OUT5 to AGND 0.5
Output Noise
VRMS
62 dB 44 1.0 2.0 k
PSRR
Internal Discharge Resistance in Shutdown VL--LINEAR REGULATOR VL Voltage VVL
IVL = 0mA to 3mA VUSB or VDC = 4.1V to 6.6V, VSYS = 2.6V to 5.5V VUSB or VDC = 4.1V to 6.6V, VSYS = 2.6V to 5.5V VLOGIC = 0V to 5.5V ISINK = 1mA VLOGIC = 5.5V TA = +25C TA = +85C TA = +25C TA = +85C
3.0
3.3
3.6
V
LOGIC (UOK, DOK, PEN1, PEN2, USUS, CEN, CST1, CST2, EN, PWM) Logic Input-Voltage Low Logic Input-Voltage High Logic Input Leakage Current Logic Output-Voltage Low Logic Output-High Leakage Current TRI-STATE INPUT (BVSET) BVSET Input-Voltage Low BVSET Input-Voltage Mid VUSB or VDC = 4.1V to 6.6V VUSB or VDC = 4.1V to 6.6V 1.2 0.3 VVL 1.2 V V 0.6 1.3 0.001 0.01 10 0.001 0.01 30 1 1 V V A mV A
______________________________________________________________________________________
11
PMIC with Integrated Charger and Smart Power Selector for Handheld Devices MAX8671X
ELECTRICAL CHARACTERISTICS (continued)
(DC, USB, BVSET, UOK, DOK, LX_ unconnected; VTHM = VL/2, VPG_ = VAGND = 0V, VBAT = 4V, CEN = low, USUS = low, EN = high, VPEN1 = VPEN2 = 3.3V, VPWM = 0V, COUT4 = 1F, COUT5 = 1F, CSYS = 10F, PV1 = PV2 = PV3 = PV4 = PV5 = SYS, RDISET = 3k, RCISET = 3k, CVL = 0.1F, CCT = 0.15F, CBP = 0.01F, VFB1 = 1.1V, VFB2 = 1.1V, VFB3 = 1.1V, TA = -40C to +85C, unless otherwise noted.) (Note 2)
PARAMETER BVSET Input-Voltage High Internal BVSET Pullup Resistance External BVSET Pulldown Resistance for Midrange Voltage RBVSET 45 SYMBOL CONDITIONS VUSB or VDC = 4.1V to 6.6V MIN VVL 0.3 52.5 50 55 TYP MAX VVL + 0.3 UNITS V k k
Note 2: Limits are 100% production tested at TA = +25C. Limits over the operating temperature range are guaranteed through correlation using statistical quality control (SQC) methods. Note 3: The USB/DC current limit does not include the VL output current. See the VL Linear Regulator section for more information. Note 4: Quiescent current excludes the energy needed for the REG1-REG5 external resistor-dividers. All typical operating characteristics include the energy for the REG1-REG5 external resistor-dividers. For the circuit of Figure 1, the typical quiescent current with DC and USB unconnected, EN = high, VBAT = 4V, and PWM = low is 175A. Note 5: The charger transitions from done to fast-charge mode at this BAT recharge threshold (Figure 7). Note 6: The charger transitions from fast-charge to top-off mode at this top-off threshold (Figure 7). Note 7: The maximum output current is guaranteed by correlation to the p-channel current-limit threshold, p-channel on-resistance, n-channel on-resistance, oscillator frequency, input voltage range, and output voltage range. The parameter is stated for a 4.7H inductor with 0.13 series resistance. See the Step-Down Converter Output Current section for more information. Note 8: The step-down output voltages are 1% high with no load due to the load-line architecture. When calculating the external resistor-dividers, use an FB_ voltage of 1.000V. Note 9: Line regulation for the step-down converters is measured as VOUT/D, where D is the duty cycle (approximately VOUT/VIN). Note 10: The skip mode current threshold is the transition point between fixed-frequency PWM operation and skip mode operation. The specification is given in terms of output load current for inductor values shown in the typical application circuits.
12
______________________________________________________________________________________
PMIC with Integrated Charger and Smart Power Selector for Handheld Devices
Typical Operating Characteristics
(Circuit of Figure 1, IVL = 0mA, TA = +25C, unless otherwise noted.)
QUIESCENT CURRENT vs. DC OR USB SUPPLY VOLTAGE
MAX8671X toc01
MAX8671X
QUIESCENT CURRENT vs. DC OR USB SUPPLY VOLTAGE
1.4 INPUT CURRENT (mA) 1.2 1.0 0.8 0.6 0.4 0.2 0 FALLING RISING CHARGER ENABLED NO BATTERY INPUT VOLTAGE AT DC OR USB WITH THE OTHER INPUT LEFT UNCONNECTED
MAX8671X toc02
USB QUIESCENT CURRENT vs. USB SUPPLY VOLTAGE, USB SUSPEND
0.45 0.40 USB CURRENT (mA) 0.35 0.30 0.25 0.20 0.15 0.10 0.05 0 USB VOLTAGE RISING 0 2 4 6 8 10 12 14 16
MAX8671X toc03
1.6 1.4 INPUT CURRENT (mA) 1.2 1.0 0.8 0.6 0.4 0.2 0 0 2 4 6 8 10 12 14 RISING CHARGER ENABLED NO BATTERY INPUT VOLTAGE AT DC OR USB WITH THE OTHER INPUT LEFT UNCONNECTED FALLING
1.6
0.50
16
0
2
4
6
8
10
12
14
16
INPUT VOLTAGE (V)
INPUT VOLTAGE (V)
USB VOLTAGE (V)
BATTERY LEAKAGE CURRENT vs. BATTERY VOLTAGE WHEN REGULATORS ARE POWERED FROM USB
MAX8671X toc04
BATTERY LEAKAGE CURRENT vs. BATTERY VOLTAGE
0.7 0.6 0.5 0.4 0.3 0.2 0.1 0 0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 BATTERY VOLTAGE (V) NO EXTERNAL POWER EN = LOW CEN = HIGH
MAX8671X toc05
1.4 BATTERY LEAKAGE CURRENT (A) 1.2 1.0 0.8 0.6 0.4 0.2 0 0 VUSB = 5V VDC = 0V PEN1 = PEN2 = 1 EN = 1
0.8 BATTERY LEAKAGE CURRENT (A)
0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 BATTERY VOLTAGE (V)
______________________________________________________________________________________
13
PMIC with Integrated Charger and Smart Power Selector for Handheld Devices MAX8671X
Typical Operating Characteristics (continued)
(Circuit of Figure 1, IVL = 0mA, TA = +25C, unless otherwise noted.)
CHARGE CURRENT vs. BATTERY VOLTAGE WITH USB INPUT
MAX8671X toc06
CHARGE CURRENT vs. BATTERY VOLTAGE
450 400 CHARGE CURRENT (mA) 350 300 250 200 150 100 VUSB = 5.0V VDC = 0V PEN1 = 1, PEN2 = 1 RCISET = 10k
MAX8671X toc07
500 450 400 CHARGE CURRENT (mA) 350 300 250 200 150 100 50 0 2.0 2.5 3.0 3.5 4.0 PEN2 = 0 VUSB = 5.0V VDC = 0V PEN1 = 1 PEN2 = 1
500
RCISET = 6.04k
50 0 4.5 2.0 2.5 3.0 3.5 4.0 4.5
BATTERY VOLTAGE (V)
BATTERY VOLTAGE (V)
CHARGE CURRENT vs. AMBIENT TEMPERATURE, LOW POWER DISSIPATION
MAX8671X toc08
CHARGE CURRENT vs. AMBIENT TEMPERATURE, HIGH IC POWER DISSIPATION
MAX8671X toc09
BATTERY REGULATION VOLTAGE vs. TEMPERATURE
4.45 4.40 BATTERY VOLTAGE (V) 4.35 4.30 4.25 4.20 4.15 4.10 VUSB = 5V VDC = 0V PEN1 = 1 PEN2 = 0 BVSET = VL NO LOAD
MAX8671X toc10
500 450 400 CHARGE CURRENT (mA) 350 300 250 200 150 100 50 0 -40 -15 10 35 60 PEN2 = 0 VUSB = 5.0V VDC = 0V VBAT = 4.0V PEN1 = 1 PEN2 = 1
500 450 400 CHARGE CURRENT (mA) 350 300 250 200 150 100 50 0 PEN2 = 0 VUSB = 6.5V VDC = 0V VBAT = 3.1V PEN1 = 1 PEN2 = 1
4.50
4.05 4.00 35 60 85 -40 -15 10 35 60 85
85
-40
-15
10
AMBIENT TEMPERATURE (C)
AMBIENT TEMPERATURE (C)
AMBIENT TEMPERATURE (C)
VSYS vs. SYS CURRENT
MAX8671X toc11
VSYS vs. SYS CURRENT
MAX8671X toc12
VSYS vs. SYS CURRENT
MAX8671X toc13
4.10 4.05 4.00 VSYS (V)
5.50
5.50
5.00
5.00
VSYS (V)
3.95 3.90 3.85 3.80 0 200 400 600 800 1000 SYS CURRENT (mA) DC OPEN, USB OPEN, VBAT = 4.0V THE SLOPE SHOWS THE SYSTEM LOAD SWITCH HAS AN ON-RESISTANCE OF 81m.
4.00
VSYS (V)
4.50
4.50
4.00
3.50 DC OPEN, VUSB = 5.1V, VBAT = 4.0V PEN1 = 1, PEN2 = 0, CHARGER DISABLED 3.00 0 200 400 600 800 1000 SYS CURRENT (mA)
3.50 DC OPEN, VUSB = 5.1V, VBAT = 4.0V PEN1 = 1, PEN2 = 0, CHARGER DISABLED 3.00 0 200 400 600 800 1000 SYS CURRENT (mA)
14
______________________________________________________________________________________
PMIC with Integrated Charger and Smart Power Selector for Handheld Devices
Typical Operating Characteristics (continued)
(Circuit of Figure 1, IVL = 0mA, TA = +25C, unless otherwise noted.)
MAX8671X
USB CONNECT (NO SYS LOAD)
MAX8671X toc14
USB CONNECT (50mA SYS LOAD)
MAX8671X toc15
USB DISCONNECT (50mA SYS LOAD)
MAX8671X toc16
VUSB IUSB VSYS VUOK IBAT 0mA -475mA CHARGING 4.0V 4.14V
VUSB 5V/div 500mA/div IUSB 2V/div 5V/div VSYS VUOK IBAT 500mA/div +50mA -425mA CHARGING 4.0V 4.14V
5V/div VUSB 500mA/div IUSB 2V/div 4.14V VSYS 4.0V
5V/div
500mA/div 2V/div 5V/div
5V/div VUOK 500mA/div IBAT +50mA -425mA CHARGING
500mA/div
2ms/div 0mA LOAD ON SYS, 4.0V BATTERY, 5.0V USB INPUT
2ms/div 50mA LOAD ON SYS, 4.0V BATTERY, 5.0V USB INPUT
2ms/div 50mA LOAD ON SYS, 4.0V BATTERY, 5.0V USB INPUT
USB SUSPEND
MAX8671X toc17
USB RESUME
MAX8671X toc18
VUSB
5V/div
VUSUS
5V/div 500mA/div 4.14V 2V/div 5V/div 5V/div +50mA -425mA 500mA/div
IUSB VSYS VCST1 VCST2 +50mA IBAT -425mA 4.14V 4.0V
500mA/div 2V/div
IUSB VSYS 4.0V
5V/div 5V/div
VCST1 VCST2 IBAT
500mA/div
400s/div 50mA LOAD ON SYS, 4.0V BATTERY, 5.0V USB INPUT
400s/div 50mA LOAD ON SYS, 4.0V BATTERY, 5.0V USB INPUT
______________________________________________________________________________________
15
PMIC with Integrated Charger and Smart Power Selector for Handheld Devices MAX8671X
Typical Operating Characteristics (continued)
(Circuit of Figure 1, IVL = 0mA, TA = +25C, unless otherwise noted.)
AC-TO-DC ADAPTER CONNECT WITH NO USB
MAX8671X toc20
AC-TO-DC ADAPTER CONNECT WITH USB
MAX8671X toc19
AC-TO-DC ADAPTER DISCONNECT WITH USB
MAX8671X toc21
VSYS
4.0V
4.14V 1A
5V/div 500mA/div
VSYS
4V
4.14V 1A
2V/div 500mA/div
VSYS 1A IDC
4V
4.14V
2V/div 500mA/div
IDC
IDC
IUSB IBAT -330mA
IUSB 500mA/div IBAT +160mA -840mA 500mA/div -840mA 400s/div 25 LOAD ON SYS, PEN1 = PEN2 = HIGH 1A DC LIMIT, RDISET = 3.01k 400s/div 25 LOAD ON SYS, PEN1 = PEN2 = HIGH 1A DC LIMIT 500mA/div IBAT -840mA
500mA/div
+160mA
-330mA 500mA/div
20ms/div 25 LOAD ON SYS, PEN1 = PEN2 = HIGH 1A DC LIMIT
POWER-UP SEQUENCING
MAX8671X toc22
VEN VOUT1 VOUT2
5V/div 5V/div 5V/div 2V/div
VOUT3 5V/div VOUT4 VOUT5 VVL IUSB 4ms/div 50mA/div 5V/div 5V/div
16
______________________________________________________________________________________
PMIC with Integrated Charger and Smart Power Selector for Handheld Devices
Typical Operating Characteristics (continued)
(Circuit of Figure 1, IVL = 0mA, TA = +25C, unless otherwise noted.)
REG1 EFFICIENCY vs. LOAD CURRENT
MAX8671X toc23
MAX8671X
REG1 LOAD REGULATION
MAX8671X toc24
REG1 DROPOUT VOLTAGE vs. LOAD CURRENT
180 160 DROPOUT VOLTAGE (mV) 140 120 100 80 60 40 20 0 THE NOMINAL INDUCTOR DC RESISTANCE IS 140m. THE NOMINAL p-CHANNEL RESISTANCE OF THE REGULATOR IS 200m AT 2.8V AND 185m AT 3.3V. THE SLOPE OF THE LINE SHOWS THAT THE TOTAL DROPOUT RESISTANCE OF AN AVERAGE PART, BOARD, INDUCTOR COMBINATION IS VOUT1 = 3.3V 330m AT 3.3V AND 354m VOUT1 = 2.8V AT 2.8V. SYS IS 100mV BELOW THE REG1 NOMINAL REGULATION VOLTAGE. 0 100 200 300 400
MAX8671X toc25
100 90 80 EFFICIENCY (%) 70 60 50 40 30 20 10 0 1 10 100 PWM = 1 VOUT1 = 2.8V VBATT = 4V PWM = 0 VOUT1 = 2.8V
2.900 2.880 2.860 OUTPUT VOLTAGE (V) 2.840 2.820 2.800 2.780 2.760 2.740 2.720 2.700 0 50 100 150 200 RFBH = 182k RFBL = 100k
200
1000
250
500
LOAD CURRENT (mA)
OUTPUT CURRENT (mA)
OUTPUT CURRENT (mA)
REG1 LIGHT-LOAD SWITCHING WAVEFORMS (PWM = 0)
MAX8671X toc26
REG1 LIGHT-LOAD SWITCHING WAVEFORMS (PWM = 1)
MAX8671X toc27
REG1 HEAVY-LOAD SWITCHING WAVEFORMS
MAX8671X toc28
VOUT1
20mV/div VOUT1 (AC-COUPLED)
VOUT1 10mV/div 10mV/div (AC-COUPLED) VLX1 2V/div 0 ILI 20mA LOAD 200ns/div 400ns/div 100mA/div 0
VLX1
2V/div 0
VLX1
2V/div 0
ILI 20mA LOAD 4s/div
200mA/div 0
ILI 20mA LOAD
100mA/div 0
REG1 LINE TRANSIENT
MAX8671X toc29
REG1 LOAD TRANSIENT
MAX8671X toc30
5.3V VSYS 3.3V 3.3V 2V/div VOUT1 50mV/div (AC-COUPLED) 250mA
VOUT1 25mA LOAD 100s/div
20mV/div
IOUT1
25mA
25mA 100mA/div
20s/div
______________________________________________________________________________________
17
PMIC with Integrated Charger and Smart Power Selector for Handheld Devices MAX8671X
Typical Operating Characteristics (continued)
(Circuit of Figure 1, IVL = 0mA, TA = +25C, unless otherwise noted.)
REG2 EFFICIENCY vs. LOAD CURRENT
90 80 EFFICIENCY (%) 70 60 50 40 30 20 10 0 1 10 100 1000 LOAD CURRENT (mA) VBATT = 4.0V 1.40 0 50 100 150 200 250 OUTPUT CURRENT (mA) PWM = 0 VOUT2 = 1.5V PWM = 1 VOUT2 = 1.5V
MAX8671X toc31
REG2 LOAD REGULATION
MAX8671X toc32
100
1.60
OUTPUT VOLTAGE (V)
1.55
1.50
1.45
REG3 EFFICIENCY vs. LOAD CURRENT
MAX8671X toc33
REG3 LOAD REGULATION
1.28 1.26 OUTPUT VOLTAGE (V) 1.24 1.22 1.20 1.18 1.16 1.14 RFBH = 20k RFBL = 100k
MAX8671X toc34
100 90 80 EFFICIENCY (%) 70 60 50 40 30 20 10 0 1 10 100 VBATT = 4.0V PWM = 0 VOUT2 = 1.2V PWM = 1 VOUT2 = 1.2V
1.30
1.12 1.10 0 50 100 150 200 250
1000
LOAD CURRENT (mA)
OUTPUT CURRENT (mA)
OUT3 LIGHT-LOAD SWITCHING WAVEFORMS (PWM = 0)
MAX8671X toc35
OUT3 HEAVY-LOAD SWITCHING WAVEFORMS
MAX8671X toc36
OUT3 LOAD TRANSIENT
MAX8671X toc37
PWM = 0 VOUT1 20mV/div VOUT1 10mV/div VOUT1 100mV/div
VLX1
2V/div 0 10mA LOAD
VLX1
2V/div 0 IOUT1 25mA
250mA
25mA 100mA/div
IL1
200mA/div
IL1 250mA LOAD
200mA/div
10s/div
400ns/div
40s/div
18
______________________________________________________________________________________
PMIC with Integrated Charger and Smart Power Selector for Handheld Devices
Typical Operating Characteristics (continued)
(Circuit of Figure 1, IVL = 0mA, TA = +25C, unless otherwise noted.) REG4 LOAD REGULATION
2.552 2.550 OUTPUT VOLTAGE (V) 2.548 2.546 2.544 2.542 2.540 2.538 2.536 2.534 0 50 100 VSYS = 4V 150 VOUT4 PV = SYS 13.4 LOAD 100s/div 10mV/div IOUT4 50mA VPV4 = VSYS = 4V VOUT4 = 2.5V 40s/div 150mA 50mA 100mV/div RFBH = 316k RFBL = 100k
MAX8671X toc38
MAX8671X
REG4 LINE TRANSIENT
MAX8671X toc39
REG4 LOAD TRANSIENT
MAX8671X toc40
2.554
5.3V VPV4 3.3V 3.3V
2V/div VOUT4 50mV/div
OUTPUT CURRENT (mA)
REG5 LOAD REGULATION
3.258 3.256 OUTPUT VOLTAGE (V) 3.254 3.252 3.250 3.248 3.246 3.244 3.242 3.240 0 50 100 VUSB = 5V 150
MAX8671X toc41
REG5 LOAD TRANSIENT
MAX8671X toc42
3.260
VOUT5
50mV/div
150mA IOUT5 50mA VUSB = 5V, VOUT5 = 3.3V 40s/div 50mA 100mV/div
OUTPUT CURRENT (mA)
______________________________________________________________________________________
19
PMIC with Integrated Charger and Smart Power Selector for Handheld Devices MAX8671X
Pin Description
PIN 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 NAME USUS DC USB FB5 PV5 OUT5 PG2 LX2 PV2 CEN FB2 DOK FB4 BP OUT4 PV4 FUNCTION USB Suspend Digital Input. As shown in Table 1, driving USUS high suspends the DC or USB inputs if they are configured as a USB power input. DC Power Input. DC is capable of delivering 1A to SYS. DC supports both AC adaptors and USB inputs. As shown in Table 1, the DC current limit is controlled by PEN1, PEN2, USUS, and RDISET. USB Power Input. USB is capable of delivering 0.5A to SYS. As shown in Table 1, the USB current limit is controlled by PEN1, PEN2, and USUS. Feedback Input for REG5. Connect FB5 to the center of a resistor voltage-divider from OUT5 to AGND to set the REG5 output voltage from 0.6V to VPV5. Power Input for REG5. Connect PV5 to SYS, or a supply between 1.7V and VSYS. Bypass PV5 to power ground with a 1F ceramic capacitor. Linear Regulator Power Output. OUT5 is internally pulled to AGND by 1k in shutdown. Power Ground for the REG2 Step-Down Regulator Inductor Switching Node for REG2. LX2 is internally pulled to PG2 by 1k in shutdown. Power Input for the REG2 Step-Down Regulator. Connect PV2 to SYS. Bypass PV2 to PG2 with a 4.7F ceramic capacitor. Active-Low Charger Enable Input. Pull CEN low to enable the charger, or drive CEN high to disable charging. The battery charger is also disabled when USUS is high. Feedback Input for REG2. Connect FB2 to the center of a resistor voltage-divider from the REG2 output capacitors to AGND to set the output voltage from 1V to VSYS. Active-Low, Open-Drain DC Power-OK Output. DOK is low when VDC is within its valid operating range. Feedback Input for REG4. Connect FB4 to the center of a resistor voltage-divider from the REG4 output capacitors to AGND to set the output voltage from 0.6V to VPV4. Reference Noise Bypass. Bypass BP with a low-leakage 0.01F ceramic capacitor for reduced noise on the LDO outputs. Linear Regulator Power Output. OUT4 is internally pulled to AGND in shutdown. Power Input for REG4. Connect PV4 to SYS, or a supply between 1.7V and VSYS. Bypass PV4 to power ground with a 1F ceramic capacitor. Battery Regulation Voltage Set Node. Drive BVSET low to set the regulation voltage to 4.1V. Connect BVSET to VL or leave unconnected to set the regulation voltage to 4.2V. Connect BVSET to AGND through a 50k resistor to set the regulation voltage to 4.350V. Ground. AGND is the low-noise ground connection for the internal circuitry. Feedback Input for REG1. Connect FB1 to the center of a resistor voltage-divider from the REG1 output capacitors to AGND to set the output voltage from 1V to VSYS. Regulator Enable Input. Drive EN high to enable all regulator outputs. The sequencing is shown in Figure 11. Drive EN low to disable the regulators. Forced-PWM Input. Connect PWM high for forced-PWM operation on REG1, REG2, and REG3. Connect PWM low for auto PWM operation. Do not change PWM on-the-fly. See the PWM section for more information. Power Input for the REG1 Step-Down Regulator. Connect PV1 to SYS. Bypass PV1 to PG1 with a 4.7F ceramic capacitor.
17 18 19 20
BVSET AGND FB1 EN
21
PWM
22
PV1
20
______________________________________________________________________________________
PMIC with Integrated Charger and Smart Power Selector for Handheld Devices MAX8671X
Pin Description (continued)
PIN 23 24 25 26 27 NAME LX1 PG1 PG3 LX3 PV3 FUNCTION Inductor Switching Node for REG1. LX1 is internally pulled to PG1 by 1k in shutdown. Power Ground for the REG1 Step-Down Regulator Power Ground for the REG3 Step-Down Regulator Inductor Switching Node for REG3. LX3 is internally pulled to PG3 by 1k in shutdown. Power Input for the REG3 Step-Down Regulator. Connect PV3 to SYS. Bypass PV3 to PG3 with a 4.7F ceramic capacitor. IC Supply Output. VL is an LDO output that powers the MAX8671X internal battery-charger circuitry. VL provides 3.3V at 3mA to power external circuitry when DC or USB is present. Connect a 0.1F capacitor from VL to AGND. Feedback Input for REG3. Connect FB3 to the center of a resistor voltage-divider from the REG3 output capacitors to AGND to set the output voltage from 1V to VSYS. DC Input Current-Limit Select Input. Connect a resistor from DISET to AGND (RDISET) to set the DC current limit. See Table 2 for more information. Charge Rate Select Input. Connect a resistor from CISET to AGND (RCISET) to set the fast-charge current limit, prequalification-charge current limit, and top-off threshold. Charge Timer Programming Node. Connect a capacitor from CT to AGND (CCT) to set the time required for a fault to occur in fast-charge or prequalification modes. Connect CT to AGND to disable the fast-charge and prequalification timers. Thermistor Input. Connect a negative temperature coefficient (NTC) thermistor that has a good thermal contact with the battery from THM to AGND. Connect a resistor equal to the thermistor resistance at +25C from THM to VL. Charging is suspended when the battery is outside the hot or cold limits. Positive Battery Terminal Connection. Connect BAT to the positive terminal of a single-cell Li+/Li-Poly battery. System Supply Output. Bypass SYS to power ground with a 10F ceramic capacitor. When a valid voltage is present at USB or DC and not suspended (USUS = low), SYS is limited to 5.3V (VSYS-REG). When the system load (ISYS) exceeds the input current limit, SYS drops below VBAT by VBSREG allowing both the external power source and the battery service SYS. SYS is connected to BAT through an internal system load switch (RBS) when a valid source is not present at USB or DC. 36 37 38 39 40 -- PEN1 CST2 UOK CST1 PEN2 EP Input Current-Limit Control 1. See Table 1 for more information. Open-Drain Charger Status Output 2. CST1 and CST2 indicate four different charger states. See Table 3 for more information. Active-Low, Open-Drain USB Power-OK Output. UOK is low when VUSB is within its valid operating range. Open-Drain Charger Status Output 1. CST1 and CST2 indicate four different charger states. See Table 3 for more information. Input Current-Limit Control 2. See Table 1 for more information. Exposed Paddle. Connect the exposed paddle to AGND. Connecting the exposed paddle does not remove the requirement for proper ground connections to AGND, PG1, PG2, and PG3.
28
VL
29 30 31
FB3 DISET CISET
32
CT
33
THM
34
BAT
35
SYS
______________________________________________________________________________________
21
PMIC with Integrated Charger and Smart Power Selector for Handheld Devices MAX8671X
AC-TO-DC ADAPTER 4.7F 2 DC SYS 35 10F SYS
VBUS 4.7F 3.3V 3mA VL 0.1F
3
USB
BAT
34 4.7F VL 10k
BAT
28
VL
THM
33 10k = 3380K 4.7H 0.6A T
18 1.8V 180mA OUT4 2.2F 121k OUT2 1.0F 15 16
AGND
+
Li+/Li-Poly
MAX8671X
OUT4 PV4 LX1
23
2.8V 425mA OUT1 182k
60.4k 3.3V 180mA OUT5 274k SYS 1.0F
13
FB4
FB1 PV1
19 22
SYS 100k 4.7F
2x 10F
6 5
OUT5 PV5 PG1 LX2 24 8
2.2F
60.4k
4
4.7H 0.6A 11 9
2.0V 425mA OUT2 100k 2x 10F 100k
FB5
FB2 PV2
SYS 4.7F
ON OFF
20 EN 21 PG2 PWM LX3 36 40 1 10 IO PEN1 PEN2 USUS CEN FB3 PV3 29 27 SYS 7 26 4.7H 0.6A
1.2V 425mA OUT3 20k 2x 10F 100k
4.7F PG3 39 37 12 38 BVSET CST1 CST2 DOK UOK BP DISET CISET CT EP 32 3k 0.15F 25 17 14 30 31 0.01F 3k
P 4x 560k 5%
Figure 1. MAX8671X Typical Application Circuit
22 ______________________________________________________________________________________
PMIC with Integrated Charger and Smart Power Selector for Handheld Devices MAX8671X
DC SYS
DOK DISET PEN1 PEN2 USUS SMART POWER SELECTOR Li+/Li-Poly BATTERY CHARGER AND SYSTEM LOAD SWITCH
BAT BVSET
UOK
CST2 CST1
USB THM CEN HIGHEST VOLTAGE SELECTOR CT CISET
VL
IN OUT 3.3V LDO
SMART POWER SELECTOR AND CHARGER BIAS
MAX8671X
AGND PV4 OUT4 FB4 REG4 LDO REG1 DC-DC PV1 LX1 PG1 FB1 BP
REF REG2 DC-DC REG5 LDO
PV2 LX2 PG2 FB2
PV5 OUT5 FB5 EN PWM
PV3 REG3 DC-DC LX3 PG3 FB3
Figure 2. Functional Diagram
______________________________________________________________________________________
23
PMIC with Integrated Charger and Smart Power Selector for Handheld Devices MAX8671X
Detailed Description
The MAX8671X highly integrated PMIC is ideally suited for use in portable audio player and handheld applications. As shown in Figure 2, the MAX8671X integrates USB power input, AC-to-DC adapter power input (DC), Li+/Li-Poly battery charger, three step-down regulators, two linear regulators, and various monitoring and status outputs. The MAX8671X offers adjustable output voltages for all outputs. When the system load requirements exceed the input current limit, the battery supplies supplemental current to the load through the internal system load switch. * When the battery is connected and there is no external power input, the system (SYS) is powered from the battery. * When an external power input is connected and there is no battery, the system (SYS) is powered from the external power input. The dual-input Smart Power Selector supports end products with dual and single external power inputs. For end products with dual external power inputs, connect these inputs directly to the DC and USB nodes of the MAX8671X. For end products with a single input, connect the single input to the DC node and connect USB to ground or leave it unconnected. In addition to AC-to-DC adapters current limits, the DC input also supports USB current limit to allow for end products
Smart Power Selector
The MAX8671X Smart Power Selector seamlessly distributes power between the two current-limited external inputs (USB and DC), the battery (BAT), and the system load (SYS). The basic functions performed are: * With both an external power supply (USB or DC) and battery (BAT) connected: When the system load requirements are less than the input current limit, the battery is charged with residual power from the input.
Table 1. Input Limiter Control Logic
POWER SOURCE DOK UOK PEN1 PEN2 USUS DC INPUT CURRENT LIMIT USB INPUT CURRENT LIMIT MAXIMUM CHARGE CURRENT* Lower of ICHGMAX and IDCLIM USB input off, DC input has priority Lower of ICHGMAX and 100mA Lower of ICHGMAX and 500mA 0 100mA Lower of ICHGMAX and 100mA Lower of ICHGMAX and 500mA 0 0
AC-to-DC Adapter at DC Input
L
X
H
X
X
IDCLIM
L USB Power at DC Input L L H USB Power at USB Input, DC Unconnected H H DC and USB Unconnected H
X
L
L
L
100mA
X X L
L L X
H X L
L H L
500mA Suspend
L L H
X X X
H X X
L H X
No DC input
500mA Suspend No USB input
*Charge current cannot exceed the input current limit. Charge can be less than the maximum charge current if the total SYS load exceeds the input current limit.
X = Don't care.
24 ______________________________________________________________________________________
PMIC with Integrated Charger and Smart Power Selector for Handheld Devices
with a single power input to operate from either an ACto-DC adapter or USB host (see Table 1). A thermal-limiting circuit reduces the battery charger rate and external power-source current to prevent the MAX8671X from overheating. USB voltage is below the battery voltage, it is considered invalid. The USB power input is disconnected when the USB voltage is invalid. As shown in Table 1, when power is available at the DC input, it has priority over the USB input. Bypass USB to ground with at least a 4.7F capacitor. To support USB power sources at the USB input drive PEN2 and USUS to select between three internally set USB-related current limits as shown in Table 1. Choose 100mA for low-power USB mode. Choose 500mA for high-power USB mode. Choose suspend to reduce the USB current to 0.11mA (typ) for both USB suspend mode and unconfigured OTG mode. To comply with the USB 2.0 specification, each device must be initially configured for low power. After USB enumeration, the device can switch from low power to high power if given permission from the USB host. The MAX8671X does not perform enumeration. It is expected that the system communicates with the USB host and commands the MAX8671X through its PEN1, PEN2, and USUS inputs. When the load exceeds the input current limit, SYS drops to 82mV below BAT and the battery supplies supplemental load current. The MAX8671X reduces the USB current limit by 5%/C when the die temperature exceeds +100C. The system load (ISYS) has priority over the charger current, so input current is first reduced by lowering charge current. If the junction temperature still reaches +120C in spite of charge current reduction, no input current is drawn from USB; the battery supplies the entire load and SYS is regulated below BAT by VBSREG. Note that this on-chip thermal-limiting circuit is not related to and operates independently from the thermistor input. If the USB power input is not required, connect USB to ground or leave it unconnected. When both DC and USB inputs are powered, the DC input has priority.
MAX8671X
System Load Switch An internal 80m (RBS) MOSFET connects SYS to BAT when no voltage source is available at DC or USB. When an external source is detected at DC or USB, this switch is opened and SYS is powered from the valid input source through the Smart Power Selector. When the system load requirements exceed the input current limit, the battery supplies supplemental current to the load through the internal system load switch. If the system load continuously exceeds the input current limit, the battery does not charge, even though external power is connected. This is not expected to occur in most cases because high loads usually occur only in short peaks. During these peaks, battery energy is used, but at all other times the battery charges. USB Power Input (USB) USB is a current-limited power input that supplies the system (SYS) up to 500mA. The USB to SYS switch is a linear regulator designed to operate in dropout. This linear regulator prevents the SYS voltage from exceeding 5.3V. USB is typically connected to the VBUS line of the universal serial bus (USB) interface. As shown in Table 1, USB supports three different current limits that are set with the PEN2 and USUS digital inputs. These current limits are ideally suited for use with USB power. The operating voltage range for USB is 4.1V to 6.6V, but it can tolerate up to 14V without damage. When the USB input voltage is below the undervoltage threshold (VUSBL, 4V typ) it is considered invalid. Similarly, if the USB voltage is above the overvoltage threshold (VUSBH, 6.9V typ) it is considered invalid. When the
______________________________________________________________________________________
25
PMIC with Integrated Charger and Smart Power Selector for Handheld Devices MAX8671X
USB Power-OK Output (UOK) As shown Figure 3, the USB power-OK output (UOK) is an active-low open-drain output. The UOK output pulls low when the voltage from USB to AGND (V USB) is between VUSBH (typically 6.9V) and VUSBL (typically 4.0V). The USB power-OK circuitry remains active in thermal overload and USB suspend. If the USB power-OK output feature is not required, connect UOK to ground or leave unconnected. USB Suspend (USUS) As shown in Table 1, driving USUS high suspends the DC or USB inputs if they are configured as a USB power input. The suspend current is 110A when USUS is driven high allowing the MAX8671X to comply with the USB 1.1/2.0 specification for USB suspend as well as the USB OTG specification for an unconfigured device. If an external input (USB or DC) is connected to the MAX8671X and suspended, the SYS node is supported by the battery. The DOK, UOK, and VL circuits remain active in USB suspend mode.
A common assumption is that REG5 is disabled in USB suspend. This is not true. REG5 is not affected by the USB suspend mode. While in suspend, a USB device must provide the 3.3V termination to the USB transceivers' pullup resistors. This 3.3V termination can come from the MAX8671X's VL output or REG5. Both remain enabled in USB suspend.
DC Power Input (DC) DC is a current-limited power input that supplies the system (SYS) up to 1A. The DC-to-SYS switch is a linear regulator designed to operate in dropout. This linear regulator prevents the SYS voltage from exceeding 5.3V. As shown in Table 1, DC supports four different current limits that are set with the PEN1, PEN2, and USUS digital inputs. These current limits are ideally suited for use with AC-to-DC wall adapters and USB power. The operating voltage range for DC is 4.1V to 6.6V, but it can tolerate up to 14V without damage. When the DC input voltage is below the undervoltage threshold (V DCL , 4V typ), it is considered invalid. Similarly, if the DC voltage is above the overvoltage threshold (VDCH, 6.9V typ), it is considered invalid. When the DC voltage is below the battery voltage, it is considered invalid. The DC power input is disconnected when the DC voltage is invalid. As shown in Table 1, when power is available at the DC input, it has priority over the USB input. Bypass DC to ground with at least a 4.7F capacitor.
USB
MAX8671X
VUSBL 4.0V RISING (typ) 500mV HYST USB UNDERVOLTAGE UOK
USB OVERVOLTAGE VUSBH 6.9V RISING (typ) 400mV HYST AGND
Figure 3. USB Power-OK Logic
26
______________________________________________________________________________________
PMIC with Integrated Charger and Smart Power Selector for Handheld Devices
To support common 500mA to 1000mA wall adapters at the DC input, pull PEN1 high. With PEN1 pulled high, the DC current limit is set by an external resistor from CISET to AGND (RCISET). Choose RCISET based on the current capability of the AC-to-DC adapter (IADPTR) as follows: RDISET 2000 x 1.5V IADPTR
Table 2. DC Current Limit for Standard Values of RDISET
RDISET (k) 3.01 3.09 3.16 3.24 3.32 3.40 3.48 3.57 3.65 3.74 3.83 3.92 4.02 4.12 4.22 IDCLIM (mA) 997 971 949 926 904 882 862 840 822 802 783 765 746 728 711 RDISET (k) 4.32 4.42 4.53 4.64 4.75 4.87 4.99 5.11 5.23 5.36 5.49 5.62 5.76 5.90 6.04 IDCLIM (mA) 694 679 662 647 632 616 601 587 574 560 546 534 521 508 497
MAX8671X
For the selected value of RDISET, calculate the DC current limit (IDCLIM) as follows (Table 2, Figure 4): 1.5V IDCLIM = 2000 x RDISET To support USB power sources at the DC input, pull PEN1 low. With PEN1 low, drive PEN2 and USUS to select between three internally set USB-related current limits as shown in Table 1. Choose 100mA for lowpower USB mode. Choose 500mA for high-power USB mode. Choose suspend to reduce the DC current to 0.11mA (typ) for both USB suspend mode and unconfigured OTG mode. To comply with the USB 2.0 specification, each device must be initially configured for low power. After USB enumeration, the device can switch from low power to high power if given permission from the USB host. When the load exceeds the current limit, SYS drops below BAT by VBSREG and the battery supplies supplemental load current. If the DC power input is not required, connect DC to ground or leave it unconnected. The MAX8671X reduces the USB and DC current limits by 5%/C when the die temperature exceeds +100C. The system load (ISYS) has priority over the charger current, so input current is first reduced by lowering charge current. If the junction temperature still reaches +120C in spite of charge-current reduction, no input current is drawn from USB and DC; the battery supplies the entire load and SYS is regulated below BAT by VBSREG. Note that this on-chip thermal-limiting circuit is not related to and operates independently from the thermistor input.
DC INPUT CURRENT LIMIT vs. DC INPUT CURRENT-LIMIT RESISTOR
1000 PEN1 = HIGH 900 IDCLIM (mA)
800
700
600
500 3.0 3.5 4.0 4.5 RDISET (k) 5.0 5.5 6.0
Figure 4. Programming DC Current Limit
DC Power-OK Output (DOK) As shown in Figure 5, the DC power-OK output (DOK) is an open-drain, active-low output. The DOK output pulls low when the voltage from DC to AGND (VDC) is between V DCH (typically 6.9V) and V DCL (typically 4.0V).
The DC power-OK circuitry remains active in thermal overload and DC suspend. If the DC power-OK output feature is not required, connect DOK to ground or leave disconnected.
______________________________________________________________________________________
27
PMIC with Integrated Charger and Smart Power Selector for Handheld Devices MAX8671X
DC
MAX8671X
VDCL 4.0V RISING (TYP) 500mV HYST USB UNDERVOLTAGE DOK
USB OVERVOLTAGE VDCH 6.9V RISING (TYP) 400mV HYST AGND
Figure 5. DC Power-OK Logic
Battery Charger
Figure 6 shows the typical Li+/Li-Poly charge profile for the MAX8671X, and Figure 7 shows the battery charger state diagram. With a valid DC and/or USB input, the battery charger initiates a charge cycle when the charger is enabled. It first detects the battery voltage. If the battery voltage is less than the prequalification threshold (3.0V), the charger enters prequalification mode in which the battery charges at 10% of the maximum fast-charge current while deeply discharged. Once the battery voltage rises to 3.0V, the charger transitions to fast-charge mode and applies the maximum charge current. As charging continues, the battery voltage rises until it approaches the battery regulation voltage (selected with BVSET) where charge current starts tapering down. When charge current decreases to 4% of the maximum fast-charge current, the charger enters a brief 15s top-off state and then charging stops. If the battery voltage subsequently drops below the battery regulation voltage by VBATRCHG, charging restarts and the timers reset. The battery charge rate is set by several factors: * Battery voltage * USB/DC input current limit * Charge setting resistor, RCISET * System load (ISYS) * Die temperature
The MAX8671X automatically reduces charge current to prevent input overload. MAX8671X also reduces charge current when in thermal regulation (see the Thermal Limiting and Overload Protection section for more information).
Battery Regulation Voltage (BVSET)
BVSET allows the maximum battery charge voltage to be set to 4.1V, 4.2V, or 4.350V. Drive BVSET low to set the regulation voltage to 4.1V. Connect BVSET to VL or leave unconnected to set the regulation voltage to 4.2V. Connect BVSET to AGND through a 45k to 55k resistor (R BVSET ) to set the regulation voltage to 4.350V. RBVSET accuracy is not critical. A 51k 5% resistor is acceptable.
Charge Enable Input (CEN)
CEN is a digital input. Driving CEN high disables the battery charger. CEN does not affect the USB or DC current limit. Driving USUS high also disables the battery charger when charging from a USB source (PEN1 = low). In many systems, there is no need for the system controller (typically a microprocessor (P)) to disable the charger because the MAX8671X independently manages the charger power path. In these situations, CEN can be connected to ground. Do not leave CEN unconnected.
28
______________________________________________________________________________________
PMIC with Integrated Charger and Smart Power Selector for Handheld Devices MAX8671X
PREQUALIFICATION FAST-CHARGE (CONSTANT CURRENT) FAST-CHARGE (CONSTANT VOLTAGE) TOP-OFF DONE
VBATREG BATTERY VOLTAGE
VBATPRQ
ICHGMAX
BATTERY CHARGE CURRENT
IPQ
ITO 0
HIGH-Z CST[1:2] CST[1:2] = 11 LOW CST[1:2] = 00
FOR SIMPLICITY, THIS FIGURE ASSUMES THAT ISYS ~ 0mA
Figure 6. Li+/Li-Poly Charge Profile
______________________________________________________________________________________
29
PMIC with Integrated Charger and Smart Power Selector for Handheld Devices MAX8671X
ICHGMAX = 2000 x 1.5V RCISET NO INPUT POWER CST [1:2] = 11 UOK = 0, DOK = 0 ICHG = 0mA USB AND DC = INVALID
USB AND/OR DC = INVALID
ANY STATE
CHARGER DISABLED CST[1:2] = 11 UOK AND/OR DOK = 1 ICHG = 0mA THERMISTOR SUSPEND ICHG = 0mA CST[1:2] = 01 UOK AND/OR DOK = 1 THM OUT OF RANGE IC SUSPENDS TIMER CEN = 0 USUS = 0 IC SETS TIMER = 0
CEN = 1 OR USUS = 1
t > tPREQUAL PREQUALIFICATION CST[1:2] = 00 UOK AND/OR DOK = 1 ICHG = ICHGMAX/10 VBAT < 2.82V IC SETS TIMER = 0 VBAT > 3.0V IC SETS TIMER = 0 t > tFST-CHG FAST-CHARGE CST[1:2] = 00 UOK AND/OR DOK = 1 THM WITHIN RANGE IC RESUMES TIMER ICHG > ICHGMAX x 7% IC SETS TIMER = 0 ICHG < ICHGMAX x 4% AND VBAT = 4.2V IC SETS TIMER = 0 ICHG < ICHGMAX x 53% OR VBAT = VBATREG IC RESUMES TIMER ICHG < ICHGMAX x 50% AND VBAT < VBATREG IC EXTENDS TIMER BY 2x TIMER EXTEND CST [1:2] = 00 (ISET x 20%) < ICHG < (ICHGMAX x 50%) VBAT < (VBATREG + VBATRCHG) IC SETS TIMER = 0 ICHG < ICHGMAX x 20% AND VBAT < VBATREG IC SUSPENDS TIMER
THM WITHIN RANGE IC RESUMES TIMER
TIMER FAULT CST [1:2] = 10 ICHG = 0mA UOK AND/OR DOK = 1
THERMISTOR SUSPEND ICHG = 0mA CST[1:2] = 01 UOK AND/OR DOK = 1
THM OUT OF RANGE IC SUSPENDS TIMER
THM OUT OF RANGE
TOP-OFF CST[1:2] = 11 UOK AND/OR DOK = 1 VBAT = VBATREG
THERMISTOR SUSPEND ICHG = 0mA CST[1:2] = 01 UOK AND/OR DOK = 1
t > 15s THM WITHIN RANGE DONE CST[1:2] = 11 UOK AND/OR DOK = 1 (VBATREG + VBATRCHG) < VBAT VBATREG ICHG = 0mA
ICHG < ICHGMAX x 23% AND VBAT = VBATREG IC RESUMES TIMER
t > 15s
TIMER SUSPEND CST [1:2] = 00 ICHG < (ICHGMAX x 20%)
Figure 7. Charger State Diagram
Charge Status Outputs (CST1, CST2)
CST1 and CST2 are open-drain charger status outputs. Their function is shown in Table 3 and Figure 7. When the MAX8671X is used with a P, pull CST1 and CST2 up to the system logic voltage with resistors to indicate
charge status to the P. Alternatively, CST1 and CST2 sink up to 20mA each for LED charge indicators. If the charge status output feature is not required, connect CST1 and CST2 to ground or leave them unconnected.
30
______________________________________________________________________________________
PMIC with Integrated Charger and Smart Power Selector for Handheld Devices
Table 3. Charge Status Outputs
CST1 0 0 1 1 CST2 0 1 0 1 CHARGING Yes No No No STATE Prequalification or fast charge Thermistor suspend Timer fault No input power or top-off or done
Table 4. Charge Times vs. CCT
CCT (nF) 68 100 150 220 470 tPQ (min) 15.0 22.0 33.0 48.4 103.4 tFC (min) 100% to 50% 299 440 660 968 2068 tFC (min) 50% to 20% 598 880 1320 1936 4136
MAX8671X
Note: CST1 and CST2 are active-low, open-drain outputs. "0" indicates that the output device is pulling low. "1" indicates that the output is high impedance.
Charge Timer (CT)
As shown in Figure 7, a fault timer prevents the battery from charging indefinitely. In prequalification and fastcharge modes, the timer is controlled by the capacitance at CT (CCT). The MAX8671X supports values of CCT from 0.01F to 1F. Calculate the prequalification and fast-charge times as follows (Table 4, Figure 8): CCT 0.15F CCT tFC = 660 min x 0.15F tPQ = 33 min x When the charger exits fast-charge mode, a fixed 15s top-off mode is entered: t TO = 15s While in the constant-current fast-charge mode (Figure 6), if the MAX8671X reduces the battery charge current due to its internal die temperature or large system loads, it slows down the charge timer. This feature eliminates nuisance charge timer faults. When the battery charge current is between 100% and 50% of its programmed fast-charge level, the fast-charge timer runs at full speed. When the battery charge current is between 50% and 20% of the programmed fast-charge level, the fast-charge timer is slowed by 2x. Similarly, when the battery charge current is below 20% of the programmed fast-charge level, the fast-charge timer is paused. The fast-charge timer is not slowed or paused when the charger is in the constant voltage portion of its fast-charge mode (Figure 6) where charge current reduces normally.
CHARGE, PREQUALIFICATION, AND TOP-OFF CURRENT vs. CHARGE SETTING RESISTOR
1000 ICHGMAX
CURRENT (mA)
100 IPQ ITO 10
1 0 5 RCISET (k) 10 15
Figure 8. Programming Charge Current
Connect CT to AGND to disable the prequalification and fast-charge timers. With the internal timers of the MAX8671X disabled, an external device, such as a P, can control the charge time through the CEN input.
Setting the Charger Currents (CISET)
As shown in Table 5 and Figure 9, a resistor from CISET to ground (R CISET ) sets the maximum fastcharge current (ICHGMAX), the charge current in prequalification mode (IPQ), and the top-off threshold (ITO). The MAX8671X supports values of I CHGMAX from 200mA to 1000mA. Select the RCISET as follows: RCISET = 2000 x 1.5V ICHGMAX
______________________________________________________________________________________
31
PMIC with Integrated Charger and Smart Power Selector for Handheld Devices MAX8671X
Table 5. Ideal Charge Currents vs. Charge Setting Resistor
RCISET (k) 3.01 4.02 4.99 6.04 6.98 8.06 9.09 10.0 11.0 12.1 13.0 14.0 15.0 ICHGMAX (mA) 1000 746 601 497 430 372 330 300 273 248 231 214 200 IPQ (mA) 100 75 60 50 43 37 33 30 27 25 23 21 20 ITO (mA) 40 30 20 17 15 13 12 11 10 9 9 8
DISCHARGING 0 BATTERY CHARGING CURRENT (A) 1.5V 2000 x R CISET 0 VCISET (V)
MONITORING THE BATTERY CHARGE CURRENT WITH VCISET
VCISET = RCISET x IBAT 2000
24
1.5
Figure 9. Monitoring the Battery Charge Current with the Voltage from CISET to AGND
Determine ICHGMAX by considering the characteristics of the battery. It is not necessary to limit the charge current based on the capabilities of the expected AC-toDC adapter or USB charging input, the system load, or thermal limitations of the PCB. The MAX8671X automatically lowers the charging current as necessary to accommodate these factors. For the selected value of RCISET, calculate ICHGMAX, IPQ, and ITO as follows: ICHGMAX = 2000 x 1.5V RCISET
directly to the CISET pin that exceeds 10pF. If filtering of the charge current monitor is necessary, include a resistor of 100k or more between CISET and the filter capacitor to preserve charger stability.
Step-Down Converters (REG1, REG2, REG3)
REG1, REG2, and REG3 are high-efficiency 2MHz current-mode, step-down converters with adjustable outputs. Each REG1, REG2, and REG3 step-down converter delivers at least 425mA. The step-down regulator power inputs (PV_) must be connected to SYS. The step-down regulators operate with V SYS from 2.6V to 5.5V. Undervoltage lockout ensures that the step-down regulators do not operate with SYS below 2.6V (typ). See the Enable/Disable (EN) and Sequencing section for how to enable and disable the step-down converters. When enabled, the MAX8671X gradually ramps each output up during a soft-start time. Soft-start eliminates input current surges when regulators are enabled. See the PWM section for information about the stepdown converters control scheme.
IPQ = 10% x ICHGMAX ITO = 4% x ICHGMAX In addition to setting the charge current, CISET also provides a means to monitor battery charge current. The CISET output voltage tracks the charge current delivered to the battery, and can be used to monitor the charge rate, as shown in Figure 9. A 1.5V output indicates the battery is being charged at the maximum set fast-charge current, and 0V indicates no charging. This voltage is also used by the charger control circuitry to set and monitor the battery current. Avoid adding capacitance
32
______________________________________________________________________________________
PMIC with Integrated Charger and Smart Power Selector for Handheld Devices
The MAX8671X uses external resistor-dividers to set the step-down output voltages between 1V and VSYS. Use at least 10A of bias current in these dividers to ensure no change in the stability of the closed-loop system. To set the output voltage, select a value for the resistor connected between FB_ and AGND (RFBL). The recommended value is 100k. Next, calculate the value of the resistor connected from FB_ to the output (RFBH): V RFBH = RFBL x OUT - 1 1.0V REG1, REG2, and REG3 are optimized for high, medium, and low output voltages, respectively. The highest overall efficiency occurs with V1 set to the highest output voltage and V3 set to the lowest output voltage. reduces switching noise in the controller. The impedance of the input capacitor at the switching frequency must be less than that of the source impedance of the supply so that high-frequency switching currents do not pass through the input source. The step-down regulator power inputs are critical discontinuous current paths that require careful bypassing. In the PCB layout, place the step-down regulator input bypass capacitors as close as possible to each pair of switching regulator power input pins (PV_ to PG_) to minimize parasitic inductance. If making connections to these caps through vias, be sure to use multiple vias to ensure that the layout does not insert excess inductance or resistance between the bypass cap and the power pins. The input capacitor must meet the input ripple current requirement imposed by the step-down converter. Ceramic capacitors are preferred due to their low ESR and resilience to power-up surge currents. Choose the input capacitor so that its temperature rise due to input ripple current does not exceed about +10C. For a step-down DC-DC converter, the maximum input ripple current is half of the output current. This maximum input ripple current occurs when the step-down converter operates at 50% duty factor (VIN = 2 x VOUT). Bypass each step-down regulator input with a 4.7F ceramic capacitor from PV_ to PG_. Use capacitors that maintain their capacitance over temperature and DC bias. Ceramic capacitors with an X7R or X5R temperature characteristic generally perform well. The capacitor voltage rating should be 6.3V or greater.
MAX8671X
PWM The MAX8671X operates in either auto-PWM or forcedPWM modes. At light load, auto PWM switches only as needed to supply the load to improve light-load efficiency of the step-down converter. At higher load currents (~100mA), the step-down converter transitions to fixed 2MHz switching. Forced PWM always operates with a constant 2MHz switching frequency regardless of the load. This is useful in low-noise applications. Permanently connect PWM high for forced-PWM applications or low for auto-PWM applications. Do not change PWM on-the-fly. Step-Down Dropout and Minimum Duty Cycle All the step-down regulators are capable of operating in 100% duty-cycle dropout; however, REG1 has been optimized for this mode of operation. During 100% duty-cycle operation, the high-side p-channel MOSFET turns on constantly, connecting the input to the output through the inductor. The dropout voltage (VDO) is calculated as follows: VDO = ILOAD (RP + RL) where:
RP = p-channel power switch RDS(on) RL = external inductor ESR The minimum duty cycle for all step-down regulators is 12.5% (typ), allowing a regulation voltage as low as 1V over the full SYS operating range. REG3 is optimized for low duty-cycle operation.
Step-Down Input Capacitors The input capacitor in a step-down converter reduces current peaks drawn from the power source and
Step-Down Output Capacitors The output capacitance keeps output ripple small and ensures control loop stability. The output capacitor must have low impedance at the switching frequency. Ceramic, polymer, and tantalum capacitors are suitable, with ceramic exhibiting the lowest ESR and lowest high-frequency impedance. The MAX8671X requires at least 20F of output capacitance, which is best achieved with two 10F ceramic capacitors in parallel. As the case sizes of ceramic surface-mount capacitors decrease, their capacitance vs. DC bias voltage characteristic becomes poor. Due to this characteristic, it is possible for 0805 capacitors to perform well while 0603 capacitors of the same value might not. The MAX8671X requires a nominal output capacitance of 20F; however, after their DC bias voltage derating, the output capacitance must be at least 15F.
______________________________________________________________________________________
33
PMIC with Integrated Charger and Smart Power Selector for Handheld Devices MAX8671X
Step-Down Inductor Choose the step-down regulator inductance to be 4.7H. The minimum recommended saturation current requirement is 600mA. In PWM mode, the peak inductor currents are equal to the load current plus one half of the inductor ripple current. The MAX8671X works well with physically small inductors. See Table 6 for suggested inductors.
The peak-to-peak inductor ripple current during PWM operation is calculated as follows: V (V - VOUT ) IP-P = OUT SYS VSYS x fS x L where fS is the 2MHz switching frequency. The peak inductor current during PWM operation is calculated as follows: I IL _ PEAK = ILOAD + P-P 2 where: VOUT = output voltage IOUTTAR = target (desired) output current--cannot be more than the minimum p-channel current-limit threshold RN = n-channel on-resistance RP = p-channel on-resistance RL = external inductor's ESR VIN = input voltage--MAXIMUM 2) Use the following equation to calculate the maximum output current (IOUTMAX): (1 - D) V ILIM - OUT 2 x f xL IOUTMAX = 1- D 1+ (RN + RL ) 2 x f xL where: ILIM = p-channel current-limit threshold--MINIMUM VOUT = output voltage D = approximate duty cycle derived from step 1 f = oscillator frequency--MINIMUM L = external inductor's inductance--MINIMUM RN = n-channel on-resistance RL = external inductor's ESR
Step-Down Converter Output Current The three MAX8671X step-down regulators each provide at least 425mA of output current when using a recommended inductor (Table 6). To calculate the maximum output current for a particular application and inductor use the following two-step process (as shown in Figure 10): 1) Use the following equation to calculate the approximate duty cycle (D):
V +I (R + RL ) D = OUT OUTTAR N VIN + IOUTTAR (RN - RP )
Table 6. Suggested Inductors
MANUFACTURER Sumida Taiyo Yuden TDK TOKO SERIES CDRH2D11HP CDH2D09 NR3012 NR3010 VLF3012 VLF3010 DE2812C DE2810C INDUCTANCE (H) 4.7 4.7 4.7 4.7 4.7 4.7 4.7 4.7 ESR () 190 218 130 190 160 240 130 180 CURRENT RATING (mA) 750 700 770 750 740 700 880 640 DIMENSIONS (mm) 3.0 x 3.0 x 1.2 = 10.8mm3 3.0 x 3.0 x 1.0 = 9.0mm3 3.0 x 3.0 x 1.2 = 10.8mm3 3.0 x 3.0 x 1.0 = 9.0mm3 2.8 x 2.6 x 1.2 = 8.7mm3 2.8 x 2.6 x 1.0 = 7.3mm3 3.0 x 2.8 x 1.2 = 10.8mm3 3.0 x 2.8 x 1.0 = 8.4mm3
34
______________________________________________________________________________________
PMIC with Integrated Charger and Smart Power Selector for Handheld Devices MAX8671X
TO FIND THE MAXIMUM OUTPUT CURRENT FOR REG3 WITH VIN = 3.2V TO 5.3V, VOUT = 1.2V, L = 4.7H 20%, AND RL = 130m : V +I (R + RL ) 1.2V + 0.425A(0.12 + 0.13) = 0.249 D = OUT OUTTAR N = VIN + IOUTTAR (RN - RP ) 5.3V + 0.425A(0.12 - 0.23) 1.2V(1- 0.249) V (1- D) 0.555A - ILIM - OUT 2 x (1.8 x 106Hz) x (4.7 x 10-6 H x 0.8) 2 x f xL = 0.482A IOUTMAX = = 1- D 1- 0.249 1+ (RN + RL ) 1+ (0.12 + 0.13) 2 x f xL 2 x (1.8 x 106Hz) x (4.7 x 10-6 H x 0.8)
Figure 10. Step-Down Converter Maximum Output Current Example
Linear Regulators (REG4, REG5)
The REG4 and REG5 linear regulators have low quiescent current, and low output noise. Each regulator supplies up to 180mA to its load. Bypass each LDO output with a 2.2F or greater capacitor to ground. If V4 or V5 is set to less than 1.5V, bypass the output with 3.3F or greater. Each linear regulator has an independent power input (PV4 and PV5) with an input voltage range from 1.7V to VSYS (VSYS can be up to 5.5V). Voltages below the input undervoltage lockout threshold (1.6V) are invalid. The regulator inputs can be driven from an efficient low-voltage source, such as a DC-DC output, to optimize efficiency (see the following equation). Bypass each LDO input with a 1F or greater capacitor to ground: V EfficiencyLDO OUT VIN REG5 is intended to power the system USB transceiver circuitry and is only active when USB power is available. REG4 is powered from the battery when power is not available at DC or USB. See the Enable/Disable (EN) and Sequencing section for how to enable and disable the linear regulators. When enabled, the linear regulators soft-start by ramping their outputs up to their target voltage in 3ms. Softstart limits the inrush current when the regulators are enabled. The MAX8671X uses external resistor-dividers to set the LDO output voltages between 0.6V and VPV_. Use at least 10A of bias current in these dividers to ensure no change in the stability of the closed-loop system. To set the output voltage, select a value for the resistor connected between FB_ and AGND (RFBL). The recom-
mended value is 60.4k. Next, calculate the value of the resistor connected from FB_ to the output (RFBH): V RFBH = RFBL x OUT - 1 0.6V For REG4, an external 0.01F bypass capacitor from BP to AGND in conjunction with a 150k internal resistor creates a 110Hz lowpass filter for noise reduction. BP is a high-impedance node and requires a low-leakage capacitor. For example, a leakage of 40nA results in a 1% error.
VL Linear Regulator
VL is the output of a 3.3V linear regulator that powers MAX8671X internal circuitry. VL is internally powered from the higher of USB or DC and automatically powers up when either of these power inputs exceeds approximately 1.5V. When the higher of the DC and USB supply is between 1.5V and 3.3V, VL operates in dropout. VL automatically powers down when both the USB and DC power inputs are removed. Bypass VL to AGND with a 0.1F capacitor. VL remains on even when USB and/or DC are in overvoltage or undervoltage lockout, when SYS is in undervoltage lockout, and also during thermal faults. VL sources up to 3mA for external loads. If VL is not used for external loads, the MAX8671X's USB/DC current limit guarantees compliance with the USB 2.0 input current specifications. If VL is used for external loads, USB/DC currents increase and might exceed the limits outlined in the USB 2.0 specification. For example, if the USB to SYS current is limited to 95mA and VL is sourcing 3mA, IUSB is 98mA. Similarly, if the USB input is suspended and VL is sourcing 3mA, IUSB is 3mA.
______________________________________________________________________________________
35
PMIC with Integrated Charger and Smart Power Selector for Handheld Devices MAX8671X
SYS SYSOK 2.5V FALLING 100mV HYST DIE TEMP PV4OK 1.6V RISING 100mV HYST PV5OK 1.6V RISING 100mV HYST USB USBOVLO 6.9V RISING 400mV HYST REGON USBPOK SOFT-START USBUVLO 4.0V RISING 500mV HYST DC DCOVLO 6.9V RISING 400mV HYST DCUVLO 4.0V RISING 500mV HYST SOFT-START EN REGON REG3OK REG1OK BIAS & REF 64 CYCLE DELAY (32ms) REG2OK DT165 SYSOK SOFT-START REGON REGON REG3OK REG1OK REG2OK REG4OK PV5OK EN OK REG5OK REG5 PV4OK EN OK REG4OK REG4 DCPOK EN REGON REG3OK REG1 EN OK REG1OK EN SOFT-START REG3 OK REG3OK DT165
PV4
MAX8671X
PV5
+165C
SOFT-START REG2 OK REG2OK
2MHz OSC
Figure 11. Enable/Disable Logic
Enable/Disable (EN) and Sequencing
Figures 11, 12, and 13 show how the five MAX8671X regulators are enabled and disabled. With a valid SYS voltage and die temperature, asserting EN high enables REG1-REG4. Pulling EN low disables
36
REG1-REG5. REG5 is intended to power the system USB transceiver circuitry, which is only active when USB power is available. Therefore, a valid source must be on either the USB or DC input for REG5 to enable.
______________________________________________________________________________________
PMIC with Integrated Charger and Smart Power Selector for Handheld Devices MAX8671X
VDC
VUSB
VVL VBAT < VSYS < (VUSB OR VDC) VSYS VBAT tD1 VEN VBAT
VOUT1
tSS1
VOUT2 tD2 VOUT3 tSS3
tSS2
tD3 tSS4
VOUT4
VOUT5
tSS5
VUOK
HIGH-Z
INTERNAL DISCHARGE RESISTORS HIGH-Z
VDOK
HIGH-Z
HIGH-Z
Figure 12. Enable and Disable Waveforms
The VL regulator is not controlled by EN. It is powered from the higher of USB or DC and automatically powers up when either of the power inputs exceeds approximately 1.5V. Similarly, VL automatically powers down when both the USB and DC power inputs are removed.
Soft-Start/Inrush Current
The MAX8671X implements soft-start on many levels to control inrush current, to avoid collapsing supply volt-
ages, and to fully comply with the USB 2.0 specifications. All USB, DC, and charging functions implement soft-start. The USB and DC nodes only require 4.7F of input capacitance. Furthermore, all regulators implement soft-start to avoid transient overload of power inputs (Figure 12).
______________________________________________________________________________________
37
PMIC with Integrated Charger and Smart Power Selector for Handheld Devices MAX8671X
Active Discharge in Shutdown
Each MAX8671X regulator (REG1-REG5) has an internal 1k resistor that discharges the output capacitor when the regulator is off. The discharge resistors ensure that the load circuitry powers down completely. The internal discharge resistors are connected when a regulator is disabled and when the device is in UVLO with an input voltage greater than 1.0V. With an input voltage less than 1.0V, the internal discharge resistors are not activated. ing range. When the USB voltage is less than the USB UVLO threshold (4.0V typ), the USB input is disconnected from SYS, and UOK goes high impedance. When the DC voltage is less than the DC UVLO threshold (4.0V typ), the DC input is disconnected from SYS, and DOK goes high impedance. In addition, when both USB and DC are in UVLO, the battery charger is disabled, and BAT is connected to SYS through the internal system load switch. REG1-REG4 are allowed to operate from the battery without power at USB or DC. REG5 is intended to power the system USB transceiver circuitry, which is only active when USB power is available. Therefore, a valid source must be present on either the USB or DC input for REG5 to enable.
Undervoltage and Overvoltage Lockout
USB/DC UVLO Undervoltage lockout (UVLO) prevents an input supply from being used when its voltage is below the operat-
UNPLUGGING USB WITH NOTHING TO DISCHARGE CUSB (VBAT = 3.3V). V5 SET FOR 3.3V UNPLUG EVENT 5V RAPID DISCHARGE UNTIL VUSB DECAYS TO THE HIGHER OF 3.5V OR VBAT + 5OmV VUSB 3.5V SLOW DISCHARGE AS THE MAX8671X DRAWS USB QUIESCENT CURRENT
HIGH-Z VUOK tDDREG5 = 120s (typ) V5
IF VBAT 3.4V, VPV5 WILL REGULATE TO 3.3V IF VBAT 3.4V, VPV5 WILL BE SLIGHTLY LESS THAN VBAT (DROPOUT)
Figure 13. REG5 Disable Detail
38
______________________________________________________________________________________
PMIC with Integrated Charger and Smart Power Selector for Handheld Devices
USB/DC OVLO Overvoltage lockout (OVLO) prevents an input supply from being used when its voltage exceeds the operating range. Both USB and DC withstand input voltages up to 14V. When the USB voltage is greater than the USB OVLO threshold (6.9V typ), the USB input is disconnected from SYS, and UOK goes high impedance. When the DC voltage is greater than the DC OVLO threshold (6.9V typ), the DC input is disconnected from SYS, and UOK goes high impedance. In addition, when both DC and USB are in OVLO, the battery charger is disabled, and BAT is connected to SYS through the internal system load switch. REG1-REG4 are allowed to operate from the battery when USB and DC are in overvoltage lockout. The VL supply remains active in OVLO. REG5 is intended to power the system USB transceiver circuitry, which is only active when USB power is available. A valid source must be present on either the USB or DC input for REG5 to enable. SYS UVLO A UVLO circuit monitors the voltage from SYS to ground (VSYS). When VSYS falls below VUVLO_SYS (2.5V typ), REG1-REG5 are disabled. V UVLO_SYS has a 100mV hysteresis. The VL supply remains active in SYS UVLO. REG4/REG5 UVLO A UVLO circuit monitors the PV4 and PV5 LDO power inputs. When the PV_ voltage is below 1.6V, it is invalid and the LDO is disabled. Smart Power Selector Thermal-Overload Protection The MAX8671X reduces the USB and DC current limits by 5%/C when the die temperature exceeds +100C. The system load (ISYS) has priority over the charger current, so input current is first reduced by lowering charge current. If the junction temperature still reaches +120C in spite of charge-current reduction, no input current is drawn from USB and DC; the battery supplies the entire load and SYS is regulated 82mV (VBSREG) below BAT. Note that this on-chip thermal-limiting circuit is not related to and operates independently from the thermistor input. Regulator Thermal-Overload Shutdown The MAX8671X disables all regulator outputs (except VL) when the junction temperature rises above +165C, allowing the device to cool. When the junction temperature cools by approximately 15C, the regulators resume the state indicated by the enable input (EN) by repeating their soft-start sequence. Note that this thermal-overload shutdown is a fail-safe mechanism; proper thermal design should ensure that the junction temperature of the MAX8671X never exceeds the absolute maximum rating of +150C. Battery Charger Thermistor Input (THM) The THM input connects to an external negative temperature coefficient (NTC) thermistor to monitor battery or system temperature. Charging is suspended when the thermistor temperature is out of range. Additionally, the charge timers are suspended and charge status indicators report that the charger is in thermistor suspend (CST[1:2] = 01). When the thermistor comes back into range, charging resumes and the charge timer continues from where it left off. Table 8 shows THM temperature limits for various thermistor material constants. If the battery temperature monitor is not required, bias THM midway between VL and AGND with a resistive divider--100k 5% resistors are recommended. Biasing THM midway between VL and AGND bypasses this function.
MAX8671X
Thermal Limiting and Overload Protection
The MAX8671X is packaged in a 5mm x 5mm x 0.8mm 40-pin thin QFN. Table 7 shows the thermal characteristics of this package. The MAX8671X has several mechanisms to control junction temperature in the event of a thermal overload.
Table 7. 5mm x 5mm x 0.8mm Thin QFN Thermal Characteristics
SINGLE-LAYER PCB Continuous Power Dissipation *JA JC 1777.8mW Derate 22.2mW/C above +70C 45C/W 1.7C/W MULTILAYER PCB 2857.1mW Derate 35.7mW/C above +70C 28C/W 1.7C/W
*JA is specified according to the JESD51 standard.
______________________________________________________________________________________
39
PMIC with Integrated Charger and Smart Power Selector for Handheld Devices MAX8671X
Table 8. Trip Temperatures for Different Thermistors
THERMISTOR BETA ( [K]) RTB (k) RTP (k) RTS (k) Resistance at +25C [k] Resistance at +50C [k] Resistance at 0C [k] Nominal Hot Trip Temperature [C] Nominal Cold Trip Temperature [C] 3000 10 Open Short 10 4.59 25.14 55 -3 3250 10 Open Short 10 4.30 27.15 53 -1 3500 10 Open Short 10 4.03 29.32 51 0 3750 10 Open Short 10 3.78 31.66 49 2 4250 10 Open Short 10 3.32 36.91 46 5 4250 10 120 Short 10 3.32 36.91 45 0
VL CEN RTB
ALTERNATE THERMISTOR CONFIGURATION
0.74 x VL THM
COLD TEMPERATURE SUSPEND HOT
RTS RTP T T ESD DIODE
0.284 x VL
AGND
BOTH COMPARATORS HAVE 65mV HYSTERESIS
MAX8671X
Figure 14. Thermistor Input
Since the thermistor monitoring circuit employs an external bias resistor from THM to VL (RTB in Figure 14), any resistance thermistor can be used as long as the value of RTB is equivalent to the thermistor's +25C resistance. For example, with a 10k at +25C thermistor, use 10k at RTB, and with a 100k at +25C thermistor, use 100k at R TB . The general relation of thermistor resistance to temperature is defined by the following equation: 1 1 RT = R25 x e - T + 273 298
40
where: RT = The resistance in ohms of the thermistor at temperature T in Celsius R 25 = The resistance in ohms of the thermistor at +25C = The material constant of the thermistor that typically ranges from 3000K to 5000K T = The temperature of the thermistor in C that corresponds to RT
______________________________________________________________________________________
PMIC with Integrated Charger and Smart Power Selector for Handheld Devices
THM threshold adjustment can be accommodated by changing RTB, connecting a resistor in series and/or in parallel with the thermistor, or using a thermistor with different material constant (). For example, a +45C hot threshold and 0C cold threshold can be realized by using a 10k thermistor with a of 4250K and connecting 120k in parallel. Since the thermistor resistance near 0C is much higher than it is near +50C, a large parallel resistance lowers the cold threshold, while only slightly lowering the hot threshold. Conversely, a small series resistance raises the cold threshold, while only slightly raising the hot threshold. Raising RTB lowers both the hot and cold thresholds, while lowering RTB raises both thresholds.
MAX8671X
TOP VIEW
8671XE TLyww + aaaa
THIN QFN 5mm x 5mm x 0.8mm
Figure 15. Package Marking Example
PCB Layout and Routing
Good printed circuit board (PCB) layout is necessary to achieve optimal performance. Refer to the MAX8671 evaluation kit for Maxim's recommended layout. Use the following guidelines for the best results: * Use short and wide traces for high-current and discontinuous current paths. * The step-down regulator power inputs are critical discontinuous current paths that require careful bypassing. Place the step-down regulator input bypass capacitors as close as possible to each switching regulator power input pair (PV_ to PG_). * Minimize the area of the loops formed by the stepdown converters' dynamic switching currents. * The exposed paddle (EP) is the main path for heat to exit the IC. Connect EP to the ground plane with thermal vias to allow heat to dissipate from the device. * The MAX8671X regulator feedback nodes are sensitive high-impedance nodes. Keep these nodes as short as possible and away from the inductors. * The thermistor node is high impedance and should be routed with care. * Make power ground connections to a power ground plane. Make analog ground connections to an analog ground plane. Connect the ground planes at a single point.
* The REG4 LDO is a high-performance LDO with high PSRR and low noise and care should be used in the layout to obtain the high performance. Generally, the REG4 LDO is powered from a stepdown regulator output, and therefore, its input capacitor should be bypassed to the power ground plane. However, its output capacitor should be bypassed to the analog ground plane. * BP is a high impedance node and leakage current into or out of BP can affect the LDO output accuracy.
Package Marking
The top of the MAX8671X package is laser etched as shown in Figure 15: * "8671XETL" is the product identification code. The full part number is MAX8671XETL; however, in this case, the "MAX" prefix is omitted due to space limitations. * "yww" is a date code. "y" is the last number in the Gregorian calendar year. "ww" is the week number in the Gregorian calendar. For example: "801" is the first week of 2008; the week of January 1st, 2008 "052" is the fifty-second week of 2010; the week of December 27th, 2010. "aaaa" is an assembly code and lot code. "+" denotes lead-free packaging and marks the pin 1 location.
Chip Information
PROCESS: BiCMOS
______________________________________________________________________________________
41
PMIC with Integrated Charger and Smart Power Selector for Handheld Devices MAX8671X
Pin Configuration
DISET PG3 PG1 PV3 VL PWM 20 EN 19 FB1 18 AGND 17 BVSET 16 PV4 15 OUT4 14 BP 13 FB4 12 DOK 11 FB2 2 DC 3 USB 4 FB5 5 PV5 6 OUT5 7 PG2 8 LX2 9 PV2 10 CEN
TOP VIEW
30 29 28 27 26 25 24 23 22 21 CISET 31 CT 32 THM 33 BAT 34 SYS 35 PEN1 36 CST2 37 UOK 38 CST1 39 PEN2 40 1 USUS
MAX8671X
+
EXPOSED PADDLE (EP)
THIN QFN 5mm x 5mm x 0.8mm
42
______________________________________________________________________________________
PV1
FB3
LX3
LX1
PMIC with Integrated Charger and Smart Power Selector for Handheld Devices
Package Information
(The package drawing(s) in this data sheet may not reflect the most current specifications. For the latest package outline information go to www.maxim-ic.com/packages.)
MAX8671X
PACKAGE OUTLINE, 16, 20, 28, 32, 40L THIN QFN, 5x5x0.8mm
21-0140
K
1
2
______________________________________________________________________________________
QFN THIN.EPS
43
PMIC with Integrated Charger and Smart Power Selector for Handheld Devices MAX8671X
Package Information (continued)
(The package drawing(s) in this data sheet may not reflect the most current specifications. For the latest package outline information go to www.maxim-ic.com/packages.)
PACKAGE OUTLINE, 16, 20, 28, 32, 40L THIN QFN, 5x5x0.8mm
21-0140
K
2
2
Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are implied. Maxim reserves the right to change the circuitry and specifications without notice at any time.
44 ____________________Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600 (c) 2007 Maxim Integrated Products is a registered trademark of Maxim Integrated Products. Inc.

▲Up To Search▲

Price & Availability of MAX8671X

	To Download MAX8671X Datasheet File
If you can't view the Datasheet, Please click here to try to view without PDF Reader .