View MAX1722_50567.PDF datasheet online --- IC-ON-LINE

Datasheet File OCR Text:

19-1735; Rev 0; 7/01
1.5A IQ, Step-Up DC-DC Converters in Thin SOT23-5
General Description
The MAX1722/MAX1723/MAX1724 compact, high-efficiency, step-up DC-DC converters are available in tiny, 5pin thin SOT23 packages. They feature an extremely low 1.5A quiescent supply current to ensure the highest possible light-load efficiency. Optimized for operation from one to two alkaline or nickel-metal-hydride (NiMH) cells, or a single Li+ cell, these devices are ideal for applications where extremely low quiescent current and ultra-small size are critical. Built-in synchronous rectification significantly improves efficiency and reduces size and cost by eliminating the need for an external Schottky diode. All three devices feature a 0.5 N-channel power switch. The MAX1722/ MAX1724 also feature proprietary noise-reduction circuitry, which suppresses electromagnetic interference (EMI) caused by the inductor in many step-up applications. The family offers different combinations of fixed or adjustable outputs, shutdown, and EMI reduction (see Selector Guide). o o o o o o o o o o o
Features
Up to 90% Efficiency No External Diode or FETs Needed 1.5A Quiescent Supply Current 0.1A Logic-Controlled Shutdown 1% Output Voltage Accuracy Fixed Output Voltage (MAX1724) or Adjustable Output Voltage (MAX1722/MAX1723) Up to 150mA Output Current 0.8V to 5.5V Input Voltage Range 0.91V Guaranteed Startup (MAX1722/MAX1724) Internal EMI Suppression (MAX1722/MAX1724) Thin SOT23-5 Package (1.1mm max Height)
MAX1722/MAX1723/MAX1724
Ordering Information
PART MAX1722EZK-T MAX1723EZK-T MAX1724EZK27-T MAX1724EZK30-T MAX1724EZK33-T MAX1724EZK50-T TEMP. RANGE -40C to +85C -40C to +85C -40C to +85C -40C to +85C -40C to +85C -40C to +85C PINPACKAGE 5 SOT23 5 SOT23 5 SOT23 5 SOT23 5 SOT23 5 SOT23 TOP MARK ADQF ADQG ADQH ADQI ADQJ ADQK
Applications
Pagers Remote Controls Remote Wireless Transmitters Personal Medical Devices Digital Still Cameras Single-Cell BatteryPowered Devices Low-Power Hand-Held Instruments MP3 Players Personal Digital Assistants (PDA)
Selector Guide
PART MAX1722EZK MAX1723EZK MAX1724EZK27 MAX1724EZK30 OUTPUT (V) Adjustable Adjustable Fixed 2.7 Fixed 3.0 Fixed 3.3 Fixed 5.0 SHDN No Yes Yes Yes Yes Yes LX DAMPING Yes No Yes Yes Yes Yes
Typical Operating Circuit
10H IN 0.8V TO 5.5V
MAX1724EZK33 MAX1724EZK50
Pin Configurations
TOP VIEW
LX
BATT
BATT
1
5
LX
MAX1724
OUT ON OFF OUT SHDN GND 3.3V AT UP TO 150mA
GND 2
MAX1722
FB 3
4
OUT
THIN SOT23-5
Pin Configurations are continued at end of data sheet.
________________________________________________________________ Maxim Integrated Products
1
For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct! at 1-888-629-4642, or visit Maxim's website at www.maxim-ic.com.
1.5A IQ, Step-Up DC-DC Converters in Thin SOT23-5 MAX1722/MAX1723/MAX1724
ABSOLUTE MAXIMUM RATINGS
OUT, SHDN, BATT, LX to GND ................................-0.3V to +6V FB to GND ................................................-0.3V to (VOUT + 0.3V) OUT, LX Current.......................................................................1A Continuous Power Dissipation (TA = +70C) 5-Pin Thin SOT23 (derate 7.1mW/C above +70C) ...571mW Operating Temperature Range ...........................-40C to +85C Junction Temperature ......................................................+150C Storage Temperature Range .............................-65C to +150C Lead Temperature (soldering, 10s) ................................ +300C
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
(VBATT = 1.2V, VOUT = 3.3V (MAX1722/MAX1723), VOUT = VOUT(NOM) (MAX1724), SHDN = OUT, RL = , TA = 0C to +85C, unless otherwise noted. Typical values are at TA = +25C.) (Note 1) PARAMETER Minimum Input Voltage Operating Input Voltage Minimum Startup Input Voltage VIN SYMBOL CONDITIONS MAX1722/MAX1724 TA = +25C TA = +25C, RL = 3k MAX1724EZK27 MAX1724EZK30 Output Voltage VOUT MAX1724EZK33 MAX1724EZK50 Output Voltage Range Feedback Voltage Feedback Bias Current N-Channel On-Resistance P-Channel On-Resistance N-Channel Switch Current Limit Switch Maximum On-Time Synchronous Rectifier ZeroCrossing Current Quiescent Current into OUT Shutdown Current into OUT Quiescent Current into BATT VOUT VFB IFB RDS(ON) RDS(ON) ILIM tON VOUT forced to 3.3V (Notes 3, 4) MAX1723/MAX1724 (Notes 3, 4) MAX1722/MAX1724 (Note 4) TA = +25C TA = +85C TA = +25C TA = +85C MAX1722/MAX1723 MAX1722/MAX1723 MAX1722/MAX1723 VOUT forced to 3.3V VOUT forced to 3.3V VOUT forced to 3.3V 400 3.5 5 TA = +25C TA = 0C to +85C TA = +25C TA = +85C MAX1722/MAX1724 MAX1723 (Note 2) MAX1722/MAX1724 MAX1723 (Note 2) TA = +25C TA = 0C to +85C TA = +25C TA = 0C to +85C TA = +25C TA = 0C to +85C TA = +25C TA = 0C to +85C 2.673 2.633 2.970 2.925 3.267 3.218 4.950 4.875 2 1.223 1.210 1.5 2.2 0.5 1.0 500 5 20 1.5 0.01 0.1 0.001 0.01 0.5 1.0 2.0 600 6.5 35 3.6 0.5 1.235 5.0 3.3 3.0 0.91 1.2 0.83 0.87 2.7 MIN TYP 0.8 5.5 5.5 0.91 1.2 2.727 2.767 3.030 3.075 3.333 3.383 5.050 5.125 5.5 1.247 1.260 20 V V nA mA s mA A A A V MAX UNITS V V V
2
_______________________________________________________________________________________
1.5A IQ, Step-Up DC-DC Converters in Thin SOT23-5
ELECTRICAL CHARACTERISTICS (continued)
(VBATT = 1.2V, VOUT = 3.3V (MAX1722/MAX1723), VOUT = VOUT(NOM) (MAX1724), SHDN = OUT, RL = , TA = 0C to +85C, unless otherwise noted. Typical values are at TA = +25C.) (Note 1) PARAMETER Shutdown Current into BATT SHDN Voltage Threshold SHDN Input Bias Current VIL VIH SYMBOL CONDITIONS MAX1724 (Note 4) MAX1723/MAX1724 MAX1723/MAX1724 MAX1723/MAX1724, V SHDN = 5.5V TA = +25C TA = +85C TA = +25C TA = +85C 75 MIN TYP 0.001 0.01 400 500 2 7 800 100 MAX 0.5 UNITS A mV nA
MAX1722/MAX1723/MAX1724
ELECTRICAL CHARACTERISTICS
(VBATT = 1.2V, VOUT = 3.3V (MAX1722/MAX1723), VOUT = VOUT(NOM) (MAX1724), SHDN = OUT, RL = , TA = -40C to +85C, unless otherwise noted.) (Note 1)
PARAMETER SYMBOL CONDITIONS MAX1724EZK27 Output Voltage VOUT MAX1724EZK30 MAX1724EZK33 MAX1724EZK50 Output Voltage Range Feedback Voltage N-Channel On-Resistance P-Channel On-Resistance N-Channel Switch Current Limit Switch Maximum On-Time Synchronous Rectifier ZeroCrossing Current Quiescent Current into OUT SHDN Voltage Threshold VIL VIH VOUT VFB RDS(ON) RDS(ON) ILIM tON VOUT forced to 3.3V (Notes 3,4) MAX1723/MAX1724 MAX1723/MAX1724 75 800 MAX1722/MAX1723 MAX1722/MAX1723 VOUT forced to 3.3V VOUT forced to 3.3V VOUT forced to 3.3V 400 3.5 5 MIN 2.633 2.925 3.218 4.875 2 1.200 TYP MAX 2.767 3.075 3.383 5.125 5.5 1.270 1.0 2.0 620 6.5 35 3.6 V V mA s mA A mV V UNITS
Note 1: Limits are 100% production tested at TA = +25C. Limits over the operating temperature range are guaranteed by design. Note 2: Guaranteed with the addition of a Schottky MBR0520L external diode between LX and OUT when using the MAX1723 with only one cell, and assumes a 0.3V voltage drop across the Schottky diode (see Figure 3). Note 3: Supply current is measured with an ammeter between the output and OUT pin. This current correlates directly with actual battery supply current, but is reduced in value according to the step-up ratio and efficiency. Note 4: VOUT forced to the following conditions to inhibit switching: VOUT = 1.05 VOUT(NOM) (MAX1724), VOUT = 3.465V (MAX1722/MAX1723).
_______________________________________________________________________________________
3
1.5A IQ, Step-Up DC-DC Converters in Thin SOT23-5 MAX1722/MAX1723/MAX1724
Typical Operating Characteristics
(Figure 3 (MAX1723), Figure 7 (MAX1722), Figure 8 (MAX1724), VBATT = VIN = 1.5V, L = 10H, CIN = 10F, COUT = 10F, TA = +25C, unless otherwise noted.)
EFFICIENCY vs. LOAD CURRENT (VOUT = 5.0V)
MAX1722 toc01
EFFICIENCY vs. LOAD CURRENT (VOUT = 3.3V)
MAX1722 toc02
EFFICIENCY vs. LOAD CURRENT (VOUT = 2.5V)
MAX1722 toc03
100 VIN = 2.0V VIN = 3.3V VIN = 4.0V
100 VIN = 2.5V
100
90 EFFICIENCY (%)
90 EFFICIENCY (%) 80
VIN = 2.0V
90 EFFICIENCY (%) VIN = 2.0V 80 VIN = 1.5V
80
70 VIN = 1.0V VIN = 1.5V L = DO1606 50 0.01 0.1 1 10 100 1000 LOAD CURRENT (mA)
70
70
60
60 VIN = 1.5V 0.01 0.1 1
VIN = 1.0V L = DO1606
60 VIN = 1.0V 50 0.01 0.1 1 10 L = DO1606 100 1000
50
10
100
1000
LOAD CURRENT (mA)
LOAD CURRENT (mA)
MAXIMUM OUTPUT CURRENT vs. INPUT VOLTAGE
MAX1722 toc04
STARTUP VOLTAGE vs. LOAD CURRENT
2.2 STARTUP VOLTAGE (V) 2.0 1.8 1.6 1.4 1.2 1.0 0.8 RESISTIVE LOAD VOUT = 5.0V
MAX1722 toc05
QUIESCENT CURRENT INTO OUT vs. OUTPUT VOLTAGE
1.8 1.6 QUIESCENT CURRENT (A) 1.4 1.2 1.0 0.8 0.6 0.4 0.2 0 NO LOAD
MAX1722 toc06 MAX1722 toc08
200 VOUT = 2.5V 160 IOUT(MAX) (mA)
2.4
2.0
120
VOUT = 5.0V
80 VOUT = 3.3V 40
0 0 1 2 3 4 5 INPUT VOLTAGE (V)
0.6 0.01 0.1 1 LOAD CURRENT (mA) 10 100
1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5 OUTPUT VOLTAGE (V)
STARTUP VOLTAGE vs. TEMPERATURE
NO LOAD 1.0 STARTUP VOLTAGE (V) 0.8 0.6 0.4 0.2 0 -40 -15 10 35 60 85 TEMPERATURE (C)
MAX1722 toc07
SWITCHING WAVEFORMS
1.2
ILX 500mA/div VOUT 50mV/div
VLX 2V/div
1s/div IOUT = 50mA, VOUT = 5.0V, VIN = 3.3V
4
_______________________________________________________________________________________
1.5A IQ, Step-Up DC-DC Converters in Thin SOT23-5 MAX1722/MAX1723/MAX1724
Typical Operating Characteristics (continued)
(Figure 3 (MAX1723), Figure 7 (MAX1722), Figure 8 (MAX1724), VBATT = VIN = 1.5V, L = 10H, CIN = 10F, COUT = 10F, TA = +25C, unless otherwise noted.)
LOAD-TRANSIENT RESPONSE
MAX1722 toc09
SHUTDOWN RESPONSE
MAX1722 toc10
3.3V
5V A
VOUT 2V/div
0 50mA B 0 0 2V VSHDN 1V/div
A: VOUT, 50mV/div B: IOUT, 20mA/div
200s/div
1ms/div VIN = 3.3V, VOUT = 5.0V, ROUT = 100
SHUTDOWN INPUT THRESHOLD vs. TEMPERATURE
0.7 SHUTDOWN THRESHOLD (mV) 0.6 RISING EDGE 0.5 0.4 FALLING EDGE 0.3 0.2 0.1 0 -40 -15 10 35 60 85 TEMPERATURE (C)
MAX1722 toc11
0.8
Pin Description
PIN NAME MAX1722 1 -- 2 3 4 5 MAX1723 -- 1 2 3 4 5 MAX1724 1 3 2 -- 4 5 BATT SHDN GND FB OUT LX Battery Input and Damping Switch Connection Shutdown Input. Drive high for normal operation. Drive low for shutdown. Ground Feedback Input to Set Output Voltage. Use a resistor-divider network to adjust the output voltage. See Setting the Output Voltage section. Power Output. OUT also provides bootstrap power to the IC. Internal N-channel MOSFET Switch Drain and P-Channel Synchronous Rectifier Drain 5 FUNCTION
_______________________________________________________________________________________
1.5A IQ, Step-Up DC-DC Converters in Thin SOT23-5 MAX1722/MAX1723/MAX1724
OUT
MAX1723
STARTUP CIRCUITRY
ZEROCROSSING DETECTOR
P SHDN CONTROL LOGIC FB ERROR COMPARATOR DRIVER LX
N
1.235V REFERENCE
CURRENT LIMIT
GND
Figure 1. MAX1723 Simplified Functional Diagram
Detailed Description
The MAX1722/MAX1723/MAX1724 compact, high-efficiency, step-up DC-DC converters are guaranteed to start up with voltages as low as 0.91V and operate with an input voltage down to 0.8V. Consuming only 1.5A of quiescent current, these devices include a built-in synchronous rectifier that reduces cost by eliminating the need for an external diode and improves overall efficiency by minimizing losses in the circuit (see Synchronous Rectification section). The MAX1722/MAX1724 feature a clamp circuit that reduces EMI due to inductor ringing. The MAX1723/MAX1724 feature an active-low shutdown that reduces quiescent supply current to 0.1A. The MAX1722/MAX1723 have an adjustable output voltage, while the MAX1724 is available with four fixed-output voltage options (see Selector Guide). Figure 1 is the MAX1723 simplified functional diagram and Figure 2 is the MAX1724 simplified functional diagram.
MAX1722/MAX1723/MAX1724. This scheme provides ultra-low quiescent current and high efficiency over a wide output current range. There is no oscillator; the inductor current is limited by the 0.5A N-channel current limit or by the 5s switch maximum on-time. Following each on cycle, the inductor current must ramp to zero before another cycle may start. When the error comparator senses that the output has fallen below the regulation threshold, another cycle begins.
Synchronous Rectification
The internal synchronous rectifier eliminates the need for an external Schottky diode, thus reducing cost and board space. While the inductor discharges, the Pchannel MOSFET turns on and shunts the MOSFET body diode. As a result, the rectifier voltage drop is significantly reduced, improving efficiency without the addition of external components.
PFM Control Scheme
A forced discontinuous, current-limited, pulse-frequencymodulation (PFM) control scheme is a key feature of the
6
Low-Voltage Startup Circuit
The MAX1722/MAX1723/MAX1724 contain a low-voltage startup circuit to control DC-DC operation until the output voltage exceeds 1.5V (typ). The minimum start-
_______________________________________________________________________________________
1.5A IQ, Step-Up DC-DC Converters in Thin SOT23-5 MAX1722/MAX1723/MAX1724
BATT DAMPING SWITCH OUT
MAX1724
STARTUP CIRCUITRY R2 P SHDN CONTROL LOGIC DRIVER LX ZEROCROSSING DETECTOR
ERROR COMPARATOR R1 1.235V REFERENCE CURRENT LIMIT
N
GND
Figure 2. MAX1724 Simplified Functional Diagram
1.2V TO VOUT
10H
10F SHDN LX OUT
D1 VOUT = 3.6V R2 2.37M FB R1 1.24M
MAX1723 GND
10F
lacks a BATT pin; therefore, this circuit is powered through the OUT pin. Adding a Schottky diode in parallel with the P-channel synchronous rectifier allows for startup voltages as low as 1.2V for the MAX1723 (Figure 3). The external Schottky diode is not needed for input voltages greater than 1.8V. Once started, the output maintains the load as the battery voltage decreases below the startup voltage.
Shutdown (MAX1723/MAX1724)
The MAX1723/MAX1724 enter shutdown when the SHDN pin is driven low. During shutdown, the body diode of the P-channel MOSFET allows current to flow from the battery to the output. VOUT falls to approximately VIN - 0.6V and LX remains high impedance. Shutdown can be pulled as high as 6V, regardless of the voltage at BATT or OUT. For normal operation, connect SHDN to the input.
Figure 3. MAX1723 Single-Cell Operation
up voltage is a function of load current (see Typical Operating Characteristics). This circuit is powered from the BATT pin for the MAX1722/MAX1724, guaranteeing startup at input voltages as low as 0.91V. The MAX1723
_______________________________________________________________________________________
7
1.5A IQ, Step-Up DC-DC Converters in Thin SOT23-5 MAX1722/MAX1723/MAX1724
VOUT VIN OUT
MAX1722 MAX1724
PDRV P BATT
TIMING CIRCUIT DAMP
DAMPING SWITCH
LX NDRV N GND
Figure 4. Simplified Diagram of Damping Switch
1V/div
1V/div
1s/div
1s/div
Figure 5. LX Ringing Without Damping Switch (MAX1723)
Figure 6. LX Ringing With Damping Switch (MAX1722/MAX1724)
BATT/Damping Switch (MAX1722/MAX1724)
The MAX1722/MAX1724 include an internal damping switch (Figure 4) to minimize ringing at LX and reduce EMI. When the energy in the inductor is insufficient to supply current to the output, the capacitance and inductance at LX form a resonant circuit that causes ringing. The damping switch supplies a path to quickly dissipate this energy, suppressing the ringing at LX. This does not reduce the output ripple, but does reduce EMI with minimal impact on efficiency. Figures 5 and 6 show the LX node voltage waveform without and with the damping switch, respectively.
Design Procedure
Setting the Output Voltage (MAX1722/MAX1723)
The output voltage can be adjusted from 2V to 5.5V using external resistors R1 and R2 (Figure 7). Since FB leakage is 20nA (max), select feedback resistor R1 in the 100k to 1M range. Calculate R2 as follows: V R2 = R1 OUT - 1 VFB where VFB = 1.235V.
8
_______________________________________________________________________________________
1.5A IQ, Step-Up DC-DC Converters in Thin SOT23-5
INPUT 0.8V TO VOUT 10H
For maximum output current, choose the inductor value so that the controller reaches the current-limit before the maximum on-time is triggered: L< VBATT t ON(MAX) ILIM
MAX1722/MAX1723/MAX1724
10F
BATT
LX OUT
OUTPUT 2V TO 5.5V
MAX1722
FB
R2
10F
where the maximum on-time is typically 5s, and the current limit (ILIM) is typically 500mA (see Electrical Characteristics table). For larger inductor values, determine the peak inductor current (IPEAK) by: IPEAK = VBATT t ON(MAX) L
R1 GND
Figure 7. Adjustable Output Circuit
Inductor Selection
The control scheme of the MAX1722/MAX1723/ MAX1724 permits flexibility in choosing an inductor. A 10H inductor value performs well in most applications. Smaller inductance values typically offer smaller physical size for a given series resistance, allowing the smallest overall circuit dimensions. Circuits using larger inductance values may start up at lower battery voltages, provide higher efficiency, and exhibit less ripple, but they may reduce the maximum output current. This occurs when the inductance is sufficiently large to prevent the maximum current limit (I LIM ) from being reached before the maximum on-time (t ON(MAX) ) expires.
INPUT 0.8V TO VOUT C1 10F
10H
BATT
LX OUT OUTPUT VOUT (NOM) C2 10F
MAX1724
ON OFF SHDN GND
Table 1. Suggested Inductors and Suppliers
MANUFACTURER Coilcraft Murata INDUCTOR DO1608 Series DO1606 Series LQH4C Series CDRH4D18 Series CR32 Series CMD4D06 Series CXLD140 Series 3DF Type D412F Type PHONE WEBSITE 847-639-2361 www.coilcraft.com 770-436-1300 www.murata.com 847-545-6700 www.sumida.com +81 (06) 6355-5733 www.daidoo.co.jp 847-297-0070 www.toko.com
Figure 8. MAX1724 Standard Application Circuit
The inductor's incremental saturation current rating should be greater than the peak switching current. However, it is generally acceptable to bias the inductor into saturation by as much as 20%, although this will slightly reduce efficiency. Table 1 lists suggested inductors and suppliers.
Maximum Output Current
The maximum output current depends on the peak inductor current, the input voltage, the output voltage, and the overall efficiency (): V 1 IPEAK BATT 2 VOUT
Sumida Sumitomo/ Daidoo Electronics Toko
IOUT(MAX) =
_______________________________________________________________________________________
9
1.5A IQ, Step-Up DC-DC Converters in Thin SOT23-5 MAX1722/MAX1723/MAX1724
Table 2. Suggested Surface-Mount Capacitors and Manufacturers (C1 and C2)
MANUFACTURER CAPACITOR VALUE 1F to 10F AVX 10F to 330F 1F to 22F Kemet 10F to 330F 68F to 330F Sanyo Taiyo Yuden TDK Vishay Sprague 33F to 330F 33F to 330F 1F to 10F 10F to 330F DESCRIPTION X7R Ceramic TAJ Tantalum Series TPS Tantalum Series X5R/X7R Ceramic T494 Tantalum Series T520 Tantalum Series TPC Polymer Series X5R/X7R Ceramic X7R Ceramic 594D Tantalum Series 595D Tantalum Series 408-749-9714 www.secc.co.jp 800-368-2496 www.t-yuden.org 847-803-6100 www.tdk.com 203-452-5664 www.vishay.com 864-963-6300 www.kemet.com 843-448-9411 www.avxcorp.com PHONE WEBSITE
For most applications, the peak inductor current equals the current limit. However, for applications using large inductor values or low input voltages, the maximum ontime limits the peak inductor current (see Inductor Selection section).
Capacitor Selection
Choose input and output capacitors to supply the input and output peak currents with acceptable voltage ripple. The input filter capacitor (CIN) reduces peak currents drawn from the battery and improves efficiency. Low equivalent series resistance (ESR) capacitors are recommended. Ceramic capacitors have the lowest ESR, but low ESR tantalum or polymer capacitors offer a good balance between cost and performance. Output voltage ripple has two components: variations in the charge stored in the output capacitor with each LX pulse, and the voltage drop across the capacitor's ESR caused by the current into and out of the capacitor: VRIPPLE = VRIPPLE(C) + VRIPPLE(ESR) VRIPPLE(ESR) IPEAK RESR(COUT) VRIPPLE(C) 1 L (IPEAK2 - IOUT2 ) V 2 ( OUT - VBATT )COUT
where IPEAK is the peak inductor current (see Inductor Selection section). For ceramic capacitors, the output voltage ripple is typically dominated by VRIPPLE(C). For example, a 10F ceramic capacitor and a 10H inductor typically provide 75mV of output ripple when stepping up from 3.3V to 5V at 50mA. Low input-to-output voltage differences (i.e. two cells to 3.3V) require higher output capacitor values. Capacitance and ESR variation of temperature should be considered for best performance in applications with wide operating temperature ranges. Table 2 lists suggested capacitors and suppliers.
PC Board Layout Considerations
Careful PC board layout is important for minimizing ground bounce and noise. Keep the IC's GND pin and the ground leads of the input and output capacitors less than 0.2in (5mm) apart using a ground plane. In addition, keep all connections to FB (MAX1722/MAX1723 only) and LX as short as possible.
Chip Information
TRANSISTOR COUNT: 863
10
______________________________________________________________________________________
1.5A IQ, Step-Up DC-DC Converters in Thin SOT23-5 MAX1722/MAX1723/MAX1724
Pin Configurations (continued)
TOP VIEW
SHDN 1 5 LX BATT 1 5 LX
GND 2
MAX1723
GND 2
MAX1724
FB 3
4
OUT
SHDN
3
4
OUT
THIN SOT23-5
THIN SOT23-5
Package Information
THIN SOT23.EPS
______________________________________________________________________________________ 11
1.5A IQ, Step-Up DC-DC Converters in Thin SOT23-5 MAX1722/MAX1723/MAX1724
Package Information (continued)
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.
12 ____________________Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600 (c) 2001 Maxim Integrated Products Printed USA is a registered trademark of Maxim Integrated Products.

▲Up To Search▲

Price & Availability of MAX1722

	To Download MAX1722 Datasheet File
If you can't view the Datasheet, Please click here to try to view without PDF Reader .