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MIC5254
Micrel
MIC5254
Dual 150mA Cap LDO with Error Flag Outputs
General Description
The MIC5254 is an efficient, precise, dual CMOS voltage regulator. It offers better than 1% initial accuracy, extremely low dropout voltage (typically 135mV at 150mA) and low ground current (typically 90A) over load. The MIC5254 features two independent LDOs with error flags that indicate an output fault condition such as overcurrent, thermal shutdown and dropout. Designed specifically for handheld and battery-powered devices, the MIC5254 provides a TTL-logic-compatible enable pin. When disabled, power consumption drops nearly to zero. The MIC5254 also works with low-ESR ceramic capacitors, reducing the amount of board space necessary for power applications, critical in handheld wireless devices. Key features include current limit, thermal shutdown, faster transient response, and an active clamp to speed up device turnoff. The MIC5254 is available in the MSOP-10 package and is rated over a -40C to +125C junction temperature range.
Features
* * * * * * Input voltage range: 2.7V to 6.0V Dual, independent 150mA LDOs Error flags indicate fault condition Stable with ceramic output capacitor Ultra-low dropout: 135mV @ 150mA High output accuracy: 1.0% initial accuracy 2.0% over temperature Low quiescent current: 90A each LDO Tight load and line regulation Thermal shutdown and current limit protection "Zero" off-mode current TTL logic-controlled enable input MSOP-10 package Cellular phones and pagers Cellular accessories Battery-powered equipment Laptop, notebook, and palmtop computers Consumer/personal electronics
* * * * * * * * * * *
Applications
Ordering Information
Part Number MIC5254-SJBMM VOUTA 3.3V VOUTB 2.5V Junction Temp. Range -40C to +125C Package MSOP-10
Other voltages available. Contact Micrel Marketing for details.
Typical Application
VINA 1mF
9
MIC5254
VINA OUTA ENA FLGA
10
VOUTA 47kW FLAGA 1mF Ceramic VOUTB 1mF Ceramic
2
1
3
GNDA OUTB VINB FLGB ENB GNDB
8 4 7
VINB 1mF
6 5
47kW FLAGB
Dual Output LDO with Error Flags
Micrel, Inc. * 1849 Fortune Drive * San Jose, CA 95131 * USA * tel + 1 (408) 944-0800 * fax + 1 (408) 944-0970 * http://www.micrel.com
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Pin Configuration
FLGA 1 ENA 2 GNDA 3 FLGB 4 ENB 5 10 OUTA 9 INA 8 OUTB 7 GNDB 6 INB
MSOP-10 (BMM)
Pin Description
Pin Number 1 2 3 9 10 4 5 7 6 8 Pin Name FLGA ENA GNDA INA OUTA FLGB ENB GNDB INB OUTB Channel A A A A A B B B B B Pin Function Error Flag (Output): Open-drain output. Active low indicates an output undervoltage condition. Enable/Shutdown (Input): CMOS compatible input. Logic high = enable; logic low = shutdown. Do not leave open. Ground. Supply Input. Regulator Output. Error Flag (Output): Open-drain output. Active low indicates an output undervoltage condition. Enable/Shutdown (Input): CMOS compatible input. Logic high = enable; logic low = shutdown. Do not leave open. Ground. Supply Input. Regulator Output.
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Absolute Maximum Ratings (Note 1)
Supply Input Voltage (VIN) .................................. 0V to +7V Enable Input Voltage (VEN) ................................. 0V to +7V Power Dissipation (PD) ............... Internally Limited, Note 3 Junction Temperature (TJ) ....................... -40C to +125C Storage Temperature ............................... -65C to +150C Lead Temperature (soldering, 5 sec.) ....................... 260C ESD, Note 4 .................................................................. 2kV
Operating Ratings (Note 2)
Input Voltage (VIN) ......................................... +2.7V to +6V Enable Input Voltage (VEN) .................................. 0V to VIN Junction Temperature (TJ) ....................... -40C to +125C Thermal Resistance MSOP-10 (JA) .................................................. 200C/W
Electrical Characteristics (Note 5)
VIN = VOUT + 1V, VEN = VIN; IOUT = 100A; TJ = 25C, bold values indicate -40C TJ +125C; unless noted. Symbol VO VLNR VLDR VIN - VOUT Parameter Output Voltage Accuracy Line Regulation Load Regulation Dropout Voltage, Note 7 Conditions IOUT = 100A VIN = VOUT + 1V to 6V IOUT = 0.1mA to 150mA, Note 6 IOUT = 100A IOUT = 100mA IOUT = 150mA IQ IGND PSRR Quiescent Current Ground Pin Current, Note 8 VEN 0.4V (shutdown) IOUT = 0mA IOUT = 150mA Power Supply Rejection f = 10Hz, VIN = VOUT + 1V; COUT = 1F f = 100Hz, VIN = VOUT + 0.5V; COUT = 1F f = 10kHz, VIN = VOUT + 0.5V ILIM en Enable Input VIL VIH IEN Enable Input Logic-Low Voltage Enable Input Logic-High Voltage Enable Input Current VIN = 2.7V to 5.5V, regulator shutdown VIN = 2.7V to 5.5V, regulator enabled VIL 0.4V, regulator shutdown VIH 1.6V, regulator enabled Shutdown Resistance Discharge Error Flag VFLG VOL IFL Low Threshold High Threshold Output Logic-Low Voltage Flag Leakage Current % of VOUT (Flag ON) % of VOUT (Flag OFF) IL = 100A, fault condition Flag OFF, VFLG = 6V 90 96 0.02 0.01 0.1 % % V A 1.6 0.01 0.01 500 0.4 V V A A Current Limit Output Voltage Noise VOUT = 0V 160 Min -1 -2 0.02 1.5 0.1 90 135 0.2 90 117 60 60 45 425 30 150 200 250 1 150 Typical Max +1 +2 0.075 2.5 Units % % %/V % mV mV mV mV A A A dB dB dB mA V(rms)
Thermal Protection Thermal Shutdown Temperature Thermal Shutdown Hysteresis
Note 1. Note 2. Note 3. Exceeding the absolute maximum rating may damage the device. The device is not guaranteed to function outside its operating rating. The maximum allowable power dissipation of any TA (ambient temperature) is PD(max) = (TJ(max)-TA)/JA. Exceeding the maximum allowable power dissipation will result in excessive die temperature, and the regulator will go into thermal shutdown. The JA of the MIC5254-SJBMM is 200C/W on a PC board (see "Thermal Considerations" section for further details).
150 10
C C
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Note 4. Note 5. Note 6. Note 7. Devices are ESD sensitive. Handling precautions recommended. Specification for packaged product only.
Micrel
Note 8.
Regulation is measured at constant junction temperature using low duty cycle pulse testing. Parts are tested for load regulation in the load range from 0.1mA to 150mA. Changes in output voltage due to heating effects are covered by the thermal regulation specification. Dropout voltage is defined as the input to output differential at which the output voltage drops 2% below its nominal value measured at 1V differential. For outputs below 2.7V, dropout voltage is the input-to-output voltage differential with the minimum input voltage 2.7V. Minimum input operating voltage is 2.7V. Ground pin current is the regulator quiescent current. The total current drawn from the supply is the sum of the load current plus the ground pin current.
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Typical Characteristics
For each LDO Channel.
Power Supply Rejection Ratio
70 60 50 PSRR (dB) 40 30 20 100A* 50mA* 100mA* 150mA*
PSRR (dB)
Power Supply Rejection Ratio
70 60 50 40 30 20 10 100A* 50mA* 100mA* 150mA* *ILOAD COUT = 4.7F Ceramic 10k 100k 100 1k FREQUENCY (Hz) 1M
PSRR (dB)
PSRR vs. Voltage Drop
70 60 50 40 30 20 10 0 0 COUT = 1F 200 400 600 800 1000 VOLTAGE DROP (mV) ILOAD = 150mA ILOAD = 100A
*ILOAD 10 C OUT = 1.0F Ceramic 0 10 100 10k 100k 1k FREQUENCY (Hz) 1M
0 10
Ground Pin Current
130 GROUND CURRENT (A)
GROUND CURRENT (A)
Ground Pin Current
115
GROUND CURRENT (A)
Ground Pin Current
125 120 115 110 105 100 I = 150mA LOAD 95 -40 -20 0 20 40 60 80 100120140 TEMPERATURE (C)
113 111 109 107 105 103 101 99 97 ILOAD = 100A
125 120 115 110 105 100 0.1 VIN = VOUT + 1V 1 10 100 1000 OUTPUT CURRENT (mA)
95 -40 -20 0 20 40 60 80 100120140 TEMPERATURE (C)
Ground Pin Current
140 140 GROUND CURRENT (A)
Ground Pin Current
3.5 OUTPUT VOLTAGE (V) 3 2.5 2 1.5 1 0.5 0 0 120 100 80 60 40 20 ILOAD = 150mA
Dropout Characteristics
100A 150mA
GROUND CURRENT (A)
120 100 80 60 40 20 ILOAD = 100A
0 0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5 INPUT VOLTAGE (V)
0 0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5 INPUT VOLTAGE (V)
1 2 3 4 5 INPUT VOLTAGE (V)
6
Dropout Voltage
0.14 180 DROPOUT VOLTAGE (mV) 160 140 120 100 80 60 40 20
Dropout Voltage
180 DROPOUT VOLTAGE (mV) 160 140 120 100 80 60 40 20 0 0
Dropout Voltage
T = -40C
DROPOUT VOLTAGE (mV)
0.12 0.1 0.08 0.06 0.04 0.02 I = 100A
T = 25C
T = 125C
0 -40 -20 0 20 40 60 80 100120140 TEMPERATURE (C)
LOAD
I
0 -40 -20 0 20 40 60 80 100120140 TEMPERATURE (C)
LOAD
= 150mA
20 40 60 80 100 120 140 160 OUTPUT CURRENT (mA)
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Typical Characteristics
For each LDO Channel.
Short Circuit Current
SHORT CIRCUIT CURRENT (mA)
SHORT CIRCUIT CURRENT (mA)
Short Circuit Current
500 V = VOUT + 1V 490 IN
OUTPUT VOLTAGE (V)
Output Voltage vs. Temperature
3.40 3.38 3.36 3.34 3.32 3.30 3.28 3.26 3.24 3.22 I = 100A LOAD 3.20 -40 -20 0 20 40 60 80 100 120 TEMPERATURE (C)
600 500 400 300 200 100 0 3 3.5 4 4.5 5 5.5 INPUT VOLTAGE (V) 6
480 470 460 450 440 430 420 410 400 -40 -20 0 20 40 60 80 100120140 TEMPERATURE (C)
ENABLE THRESHOLD VOLTAGE (V)
Enable Threshold vs. Temperature
1.3 4.5 4 1.25 1.2 1.15 1.1 1.05 1 0.95 0.9 0.85 I 0.8 -40 -20 0 20 40 60 80 100120140 TEMPERATURE (C)
LOAD
Error Flag Pull-Up Resistor
Power Good
FLAG VOLTAGE (V)
3.5 3 2.5 2 1.5 1 0.5 0 0.1 1 Power Fail 10 100 1000 10000 RESISTANCE (k) VIN = 4V
= 100A
Test Circuit
VINA 1F MIC5254
9
VINA OUTA ENA FLGA
10
VOUTA 47k
2
1
FLAGA 0.01F
1F Ceramic VOUTB
3
GNDA OUTB VINB ENB FLGB GNDB
8
VINB 1F
47k
6 5 4 7
FLAGB 0.01F
1F Ceramic
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Functional Characteristics
For each LDO Channel
Load Transient Response
Output Voltage (50mV/div)
Line Transient Response
CIN = 1F Ceramic COUT = 1F Ceramic IOUT = 100A
CIN = 1F Ceramic COUT = 1F Ceramic VIN = 4V
100A
TIME (4s/div)
Output Voltage (50mV/div)
Output Current (100mA/div)
150mA
Input Voltage (1V/div)
TIME (400s/div)
Enable Pin Delay
Enable Voltage (1V/div)
Shutdown Delay
Enable Voltage (1V/div)
CIN = 1F Ceramic COUT = 1F Ceramic IOUT = 150mA
CIN = 1F Ceramic COUT = 1F Ceramic IOUT = 150mA
Output Voltage (1V/div)
TIME (10s/div)
Output Voltage (1V/div)
TIME (10s/div)
Error Flag Start-up*
Enable Voltage (2V/div)
Enable Voltage (2V/div)
Error Flag Shutdown*
Output Voltage (2V/div)
Error Flag (2V/div)
TIME (400s/div)
Error Flag (2V/div)
Output Voltage (2V/div)
TIME (400s/div)
* See Test Circuit
* See Test Circuit
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Functional Diagram
INA ENA Reference Voltage Startup/ Shutdown Control Quickstart
Thermal Sensor
FAULT
Error Amplifier
Current Amplifier
OUTA
Undervoltage Lockout
ACTIVE SHUTDOWN
Out of Regulation Detection FLGA Overcurrent Dropout Detection GNDA INB ENB Reference Voltage Startup/ Shutdown Control Quickstart
Thermal Sensor
FAULT
Error Amplifier
Current Amplifier
OUTB
Undervoltage Lockout
ACTIVE SHUTDOWN
Out of Regulation Detection FLGB Overcurrent Dropout Detection GNDB
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input without using a pull-down capacitor, there can be a glitch on the error flag upon start up of the device. This is due to the response time of the error flag circuit as the device starts up. When the device comes out of the "zero" off mode current state, all the various nodes of the circuit power up before the device begins supplying full current to the output capacitor. The error flag drives low immediately and then releases after a few microseconds. The intelligent circuit that triggers an error detects the output going into current limit AND the output being low while charging the output capacitor. The error output then pulls low for the duration of the turn-on time. A capacitor from the error flag to ground will filter out this glitch. The glitch does not occur if the error flag pulled up to the output. Active Shutdown The MIC5254 also features an active shutdown clamp, which is an N-Channel MOSFET that turns on when the device is disabled. This allows the output capacitor and load to discharge, de-energizing the load. No Load Stability The MIC5254 will remain stable and in regulation with no load unlike many other voltage regulators. This is especially important in CMOS RAM keep-alive applications. Thermal Considerations The MIC5254 is a dual LDO voltage regulator designed to provide two output voltages from one package. Both regulator outputs are capable of sourcing 150mA of output current. Proper thermal evaluation needs to be done to ensure that the junction temperature does not exceed it's maximum value, 125C. Maximum power dissipation can be calculated based on the output current and the voltage drop across each regulator. The sum of the power dissipation of each regulator determines the total power dissipation. The maximum power dissipation that this package is capable of handling can be determined using thermal resistance, junction to ambient, and the following basic equation: TJ(max) - TA PD(max) = JA TJ(max) is the maximum junction temperature of the die, 125C and TA is the ambient operating temperature of the die. JA is layout dependent. Table 1 shows the typical thermal resistance for a minimum footprint layout for the MIC5254.
Package MSOP-10 JA at Recommended Minimum Footprint 200C/W
Applications Information
Enable/Shutdown The MIC5254 comes with an active-high enable pin for each regulator that allows the regulator to be disabled. Forcing the enable pin low disables the regulator and sends it into a "zero" off-mode-current state. In this state, current consumed by the regulator goes nearly to zero. Forcing the enable pin high enables the output voltage. This part is CMOS and the enable pin cannot be left floating; a floating enable pin may cause an indeterminate state on the output. Input Capacitor The MIC5254 is a high performance, high bandwidth device. Therefore, it requires a well-bypassed input supply for optimal performance. A 1F capacitor is required from the input to ground to provide stability. Low ESR ceramic capacitors provide optimal performance at a minimum of space. Additional high-frequency capacitors, such as small-valued NPO dielectric type capacitors, help filter out high frequency noise and are good practice in any RF based circuit. Output capacitor The MIC5254 requires an output capacitor for stability. The design requires 1F or greater on the output to maintain stability. The design is optimized for use with low ESR ceramic chip capacitors. High ESR capacitors may cause high frequency oscillation. The maximum recommended ESR is 300m. The output capacitor can be increased, but performance has been optimized for a 1F ceramic output capacitor and does not improve significantly with larger capacitance. X7R/X5R dielectric-type ceramic capacitors are recommended because of their temperature performance. X7Rtype capacitors change capacitance by 15% over their operating temperature range and are the most stable type of ceramic capacitors. Z5U and Y5V dielectric capacitors change value by as much as 50% and 60% respectively over their operating temperature ranges. To use a ceramic chip capacitor with Y5V dielectric, the value must be much higher than an X7R ceramic capacitor to ensure the same minimum capacitance over the equivalent operating temperature range. Error Flag The error flag output is an active-low, open-drain output that drives low when a fault condition AND an undervoltage detection occurs. Internal circuitry intelligently monitors overcurrent, overtemperature and dropout conditions and ORs these outputs together to indicate some fault condition. The output of that OR gate is ANDed with an output voltage monitor that detects an undervoltage condition. That output drives the open-drain transistor to indicate a fault. This prevents chattering or inadvertent triggering of the error flag. The error flag must be pulled-up using a resistor from the flag pin to either the input or the output. The error flag circuit was designed essentially to work with a capacitor to ground to act as a power-on reset generator, signaling a power-good situation once the regulated voltage was up and/or out of a fault condition. This capacitor delays the error signal from pulling high, allowing the downstream circuits time to stabilize. When the error flag is pulled-up to the September 2003 9
Table 1. Thermal Resistance The actual power dissipation of each regulator output can be calculated using the following simple equation: PD = (VIN - VOUT)IOUT + VIN x IGND Each regulator contributes power dissipation to the overall power dissipation of the package. PD(total) = PD(reg1) + PD(reg2)
MIC5254
MIC5254
Each output is rated for 150mA of output current, but the application may limit the amount of output current based on the total power dissipation and the ambient temperature. A typical application may call for one 3.3V output and one 2.5V output from a single Li-Ion battery input. This input can be as high as 4.2V. When operating at high ambient temperatures, the output current may be limited. When operating at an ambient of 60C, the maximum power dissipation of the package is calculated as follows: 125C - 60C PD(max) = 200C/W PD = 325mW For the application mentioned above, if regulator 1 is sourcing 150mA, it contributes the following to the overall power dissipation: PD(reg2) = (VIN - VOUT)IOUT + VIN x IGND PD(reg1) = (4.2V - 3.3V)150mA + 4.2V x 100A
Micrel
PD(reg1) = 135.5mW Since the total power dissipation allowable is 325mW, the maximum power dissipation of the second regulator is limited to: PD(max) = PD(reg1) + PD(reg2) 325mW = 135.5mW + PD(reg2) PD(reg2) = 189.5mW The maximum output current of the second regulator can be calculated using the same equations but solving for the output current (ground current is constant over load and simplifies the equation): PD(reg2) = (VIN - VOUT)IOUT + VIN x IGND 189.5mW = (4.2V - 2.5V)IOUT + 4.2V x 100A IOUT = 111.2mA The second output is limited to 110mA due to the total power dissipation of the system when operating at 60C ambient temperature.
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Package Information
3.15 (0.122) 2.85 (0.114)
4.90 BSC (0.193)
DIMENSIONS: MM (INCH)
3.10 (0.122) 2.90 (0.114) 1.10 (0.043) 0.94 (0.037)
0.26 (0.010) 0.10 (0.004)
0.30 (0.012) 0.15 (0.006) 0.50 BSC (0.020)
0.15 (0.006) 0.05 (0.002)
6 MAX 0 MIN
0.70 (0.028) 0.40 (0.016)
10-Pin MSOP (BMM)
MICREL, INC. 1849 FORTUNE DRIVE SAN JOSE, CA 95131
TEL
USA
+ 1 (408) 944-0800
FAX
+ 1 (408) 944-0970
WEB
http://www.micrel.com
The information furnished by Micrel in this datasheet is believed to be accurate and reliable. However, no responsibility is assumed by Micrel for its use. Micrel reserves the right to change circuitry and specifications at any time without notification to the customer. Micrel Products are not designed or authorized for use as components in life support appliances, devices or systems where malfunction of a product can reasonably be expected to result in personal injury. Life support devices or systems are devices or systems that (a) are intended for surgical implant into the body or (b) support or sustain life, and whose failure to perform can be reasonably expected to result in a significant injury to the user. A Purchaser's use or sale of Micrel Products for use in life support appliances, devices or systems is at Purchaser's own risk and Purchaser agrees to fully indemnify Micrel for any damages resulting from such use or sale. (c) 2003 Micrel, Incorporated.
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MIC5254

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