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MIC5312
LowQTM Mode Dual 300mA LDO with Integrated POR
General Description
The MIC5312 is a high performance, dual Cap low dropout regulator with integrated power-on reset supervisor, offering ultra-low operating current and a second, even lower operating current mode, LowQTM mode, reducing operating current by 75%. Each regulator can source up to 300mA of output current maximum. Ideal for battery operated applications, the MIC5312 offers 1% accuracy, extremely low dropout voltage (60mV @ 150mA), and low ground current (typically 28A total). When put into LowQTM mode, the internal current draw drops down to 7A total. The MIC5312 also comes equipped with a TTL logic compatible enable pin that allows the part to be put into a zero-offmode current state, drawing no current when disabled. The Power-on Reset is active low and indicates an output undervoltage condition on either regulator 1 or 2 when the regulator is enabled. The MIC5312 is a Cap design, operating with very small ceramic output capacitors for stability, reducing required board space and component cost. The MIC5312 is available in fixed output voltages in the 3mm x 3mm MLF-10 leadless package. Data sheets and support documentation can be found on Micrel's web site at www.micrel.com.
Features
* Input voltage range: 2.5V to 5.5V * LowQTM Mode - 7A total quiescent current - 10mA output current capable LowQTM mode - Logic level control with external pin * Stable with ceramic output capacitor * 2 LDO Outputs - 300mA each * Integrated Power-on Reset (POR) with adjustable delay time * Tiny 3mm x 3mm MLFTM-10 package * Low dropout voltage of 60mV @ 150mA * Ultra-low quiescent current of 28A total in Full Current Mode * High output accuracy - 1.0% initial accuracy - 2.0% over temperature * Thermal Shutdown Protection * Current Limit Protection
Applications
* * * * Cellular/PCS phones Wireless modems PDAs MP3 Players
Typical Application
VIN EN1 EN2 LOWQ BYP GND SET VOUT1 VOUT2 POR VCORE VI/O Baseband Processor
MIC5312-xxBML
MLF and MicroLeadFrame are trademarks of Amkor Technology, Inc. Micrel Inc. * 2180 Fortune Drive * San Jose, CA 95131 * USA * tel +1 (408) 944-0800 * fax + 1 (408) 474-1000 * http://www.micrel.com
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Micrel, Inc.
MIC5312
Ordering Information
Part Number MIC5312-GMBML MIC5312-DKBML Output Voltage* 1.8V/2.8V 1.85V/2.6V Junction Temp. Range -40C to +125C -40C to +125C Package 10-Pin 3x3 MLFTM 10-Pin 3x3 MLFTM
Note: *Other Voltage options available between 1.25V and 5V. Contact Micrel for details.
Pin Configuration
VIN 1 EN1 2 EN2 3 LOWQ 4 BYP 5 10 VOUT1 9 VOUT2 8 POR 7 SET 6 GND
MIC5312-xxBML (3x3)
Pin Description
Fixed 1 2 3 4 5 6 7 8 9 10 EP Pin Name VIN EN1 EN2 LowQTM BYP GND SET POR VOUT2 VOUT1 GND Pin Function Supply Input. (VIN1 and VIN2 are internally tied together) Enable Input (regulator 1). Active High Input. Logic High = On; Logic Low = Off; Do not leave floating Enable Input (regulator 2). Active High Input. Logic High = On; Logic Low = Off; Do not leave floating LowQTM Mode. Active Low Input. Logic High = Full Power Mode; Logic Low = Light Load Mode; Do not leave floating. Reference Bypass: Connect external 0.01F to GND to reduce output noise. May be left open. Ground. Delay Set Input: Connect external capacitor to GND to set the internal delay for the POR output. When left open, there is no delay. This pin cannot be grounded. Delay = 1s/1pF Power-On Reset Output: Open-drain output. Active low indicates an output undervoltage condition on either regulator 1 or regulator 2 when device is enabled. Output of regulator 2 Output of regulator 1 Ground. Internally connected to the Exposed Pad.
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Absolute Maximum Ratings(1)
Supply Input Voltage (VIN) .............................. 0V to 6V Enable Input Voltage (VEN)............................. 0V to 6V LowQTM Input Voltage (VLowQTM)...................... 0V to 6V Power Dissipation (PD) ..................Internally Limited (3) Junction Temperature ....................... -40C to +125C Lead Temperature (soldering, 5sec.) .................260C Storage Temperature (Ts) ................. -65C to +150C
Operating Ratings(2)
Supply Input Voltage (VIN)..........................2.5V to 5.5V Enable Input Voltage (EN1/EN2/LowQTM) ...... 0V to VIN Junction Temperature (TJ) .................. -40C to +125C Package Thermal Resistance MLF-10 (JA) ................................................. 63C/W
Electrical Characteristics (Full Power Mode)
VIN = VOUT + 1.0V for higher output of the regulator pair; LowQTM = VIN; COUT = 2.2F, IOUT = 100A; TJ = 25C, bold values indicate -40C to +125, unless noted.
Parameter Output Voltage Accuracy Line Regulation Load Regulation Dropout Voltage Ground Pin Current Ground Pin Current in Shutdown Ripple Rejection Conditions Variation from nominal VOUT Variation from nominal VOUT; -40C to +125C VIN = VOUT +1V to 5.5V IOUT = 100A to 150mA IOUT = 100A to 300mA IOUT = 150mA IOUT = 300mA IOUT1 = IOUT2 = 100A to 300mA VEN < 0.2V Min -1.0 -2.0 Typ Max +1.0 +2.0 0.3 0.6 1.0 1.5 240 45 50 Units % % %/V % % mV mV A A A dB dB mA Vrms V V A A s s s % % V A A V
0.02 0.35 0.7 60 120 28 0.1 65 35 450 45
f = up to 1kHz; COUT = 2.2F ceramic; CBYP = 10nF f = 1kHz - 20kHz; COUT = 2.2F ceramic; CBYP = 10nF Current Limit VOUT = 0V (Both Regulators) Output Voltage Noise COUT = 2.2F, CBYP = 0.01F, 10Hz to 100kHz Enable and LowQTM Input (EN1/EN2/LowQTM) Enable Input Voltage Logic Low Logic High Enable Input Current VIL < 0.2V VIH > 1.0V Turn-on Time COUT = 2.2F; CBYP = 0.01F Light Load Response Response Time (4) Into Light Load Out of Light Load POR Output VTH Low Threshold, % of VOUT(Flag ON) High Threshold, % of VOUT (Flag OFF) VOL POR Output Logic Low Voltage; IL = 250A IPOR Flag Leakage Current, Flag OFF SET INPUT SET Pin Current Source SET Pin Threshold Voltage VSET = 0V
350
700
0.2 1.0 0.1 0.1 300 50 50 90 0.01 0.01 1.25 1.25 97 0.1 +1 1.75 1 1 500
-1 0.75
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MIC5312
Electrical Characteristics (LowQTM Mode)
VIN = VOUT + 1.0V for higher output of the regulator pair; LowQTM = 0V; COUT = 2.2F, IOUT = 100A; TJ = 25C, bold values indicate -40C to +125C, unless noted.
Parameter Output Voltage Accuracy Line Regulation Load Regulation Dropout Voltage Ground Pin Current Ground Pin Current in Shutdown Ripple Rejection Current Limit
Notes: 1. Exceeding the absolute maximum rating may damage the device. 2. The device is not guaranteed to function outside its operating rating. 3. 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. 4. Response time defined as the minimum hold-off time after the LowQTM command before applying load transients.
Conditions Variation from nominal VOUT VIN = VOUT +1V to 5.5V IOUT = 100A to 10mA IOUT = 10mA Both outputs enabled VEN < 0.2V f = up to 1kHz; COUT = 2.2F ceramic; CBYP = 10nF f = 1kHz - 20kHz; COUT = 2.2F ceramic; CBYP = 10nF VOUT = 0V (Both regulators)
Min -2.0 -3.0
Typ
Max +2.0 +3.0 0.3 0.6 0.5 200 10 12 1.0
Units % % %/V % mV A A A dB dB mA
0.02 0.1 100 7 0.01 45 30 75
40
150
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Typical Characteristics
Ripple Rejection vs. I LOAD (Normal Mode)
90 80 70 PSRR (dB) PSRR (dB) 60 50 40 50mA 150mA 90 80 70 60 50 40 . 30 VOUT=1.85V VIN=VOUT+1V 20 =10mA I LOAD 10 C = 2.2 F Ceramic 0 10
OUT
Ripple Rejection LowQ Mode
OUTPUT VOLTAGE (V)
2.7 2.65 2.6 2.55 2.5 2.45 2.4 2.35 2.3 0
Output Voltage vs. Temperature
30 VOUT=1.85V +1V V =V 20 IN OUT = 2.2F C 10 OUT C = 10nF 300mA BYP 0 10 1k 100 10k 100k 1M FREQUENCY (Hz)
1k 100 10k 100k 1M FREQUENCY (Hz)
100A 25
50
75
100
125
3 OUTPUT VOLTAGE (V) 2.5 2 1.5 1 0.5
Dropout Characteristics
DROPOUT VOLTAGE (mV)
160
Dropout vs. Temperature (Normal Mode)
DROPOUT VOLTAGE (mV) 300mA
140 120 100
Dropout vs. Temperature (LowQ Mode)
10mA
100mA 150mA 300mA
140 120 100 80 60 40 20 0 -40 -20 0
80 60 40 20 0 -40 -20 0
150mA
6mA 3mA
50mA
0 0
VOUT=2.6V 1 2 3 4 5 SUPPLY VOLTAGE (V) 6
20 40 60 80 100 120
20 40 60 80 100 120
35 GROUND CURRENT (A) 30 25 20 15 10 5
Ground Current vs. Supply Voltage
300mA GROUND CURRENT (A) 100mA
35 30 25 20 15 10 5
Ground Current vs. Temperature
50mA 150mA 300mA
Ground Current vs. Temperature (LowQ Mode)
9 8 7 6 5 4 3 2 1 0 -40 -20 0 20 40 60 80 100 120 GROUND CURRENT (A) 10mA 100A
150mA
100mA
10mA LowQTM
0 1.3 1.8 2.3 2.8 3.3 3.8 4.3 4.8 5.3 SUPPLY VOLTAGE (V)
0 -40 -20 0
20 40 60 80 100 120
1
NOISE (V/rootHz)
Output Noise Spectral Density
0.1
0.01 VIN = 4.45V COUT = 2.2 F CBYP = 0.01F VOUT = 1.8V R 0.001 OUT 10 100 1k 10k 100k 1M 10M FREQUENCY (Hz)
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MIC5312
Functional Characteristics
Enable On- Normal
VEN (500mV/div)
Enable Off - Normal
VEN (500mV/div)
ILOAD = 200mA VOUT = 2.6V VOUT (1V/div) ILOAD = 200mA VOUT = 2.6V
Time (40s/div)
VOUT (1V/div)
Time (10s/div)
Line Transient - LowQ
VIN (1V/div) VIN (1V/div)
Line Transient - Normal
5.5V
5.5V
4V VOUT (20mV/div)
4V
VOUT (50mV/div)
VOUT = 2.6V VIN = VOUT + 1V COUT = 2.2F LowQ = 0V ILOAD = 10mA Time (200s/div)
ILOAD = 300mA VOUT = 2.6V COUT = 2.2F LowQ = 5.5V Time (40s/div)
Load Transient - LowQ
IOUT (100mA/div) 300mA
Load Transient - Normal
IOUT (10mV/div)
10mA 0mA
100A VOUT (20mV/div)
VOUT (10mV/div)
VOUT = 2.6V VIN = VOUT + 1V COUT = 2.2F Time (200s/div)
VOUT = 2.6V VIN = VOUT + 1V COUT = 2.2F Time (1ms/div)
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MIC5312
Functional Characteristics (cont.)
Normal to LowQ Transien t
LowQTM (1V/div) Normal LowQ
TM
LowQ to Normal Transien t
LowQTM (1V/div) LowQ
TM
Normal
VOUT2 VOUT1 (500mV/div) (500mV/div)
VOUT1 VOUT2 (500mV/div) (500mV/div)
ILOAD = 10mA
ILOAD = 10mA
Time (40s/div)
Time (40s/div)
VOUT2 (2V/div)
VOUT1 (1V/div)
VEN = EN1 = EN2 (1V/div)
Power-On Reset Characteristics
POR (2V/div)
COUT = 2.2F CSET = 0.01F CBYP = 0.01F VIN = 5.0V ILOAD = 10mA Time (2ms/div)
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MIC5312
Functional Diagram
VIN LDO1 EN1 LOWQ LowQTM VOUT2 LDO2 EN2 POR & Delay POR SET BYP Reference VOUT1
GND
MIC5312 Block Diagram
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MIC5312
Functional Description
The MIC5312 is a high performance, low quiescent current power management IC consisting of two Cap low dropout regulators with a LowQTM mode featuring lower operating current. Both regulators are capable of sourcing 300mA. A POR circuit monitors both of the outputs and indicates when the output voltage is within 5% of nominal. The POR offers a delay time that is externally programmable with a single capacitor to ground. Enable 1 and 2 The enable inputs allow for logic control of both output voltages with individual enable inputs. The enable input is active high, requiring 1.0V for guaranteed operation. The enable input is CMOS logic and cannot be left floating. There are two regulators in the MIC5312 that share a common bias. Each regulator can be enabled independently by setting the voltage on pins EN1 and EN2 to either logic high or low to turn the channel on or off. It is also possible to enable both channels by applying a voltage above 1.0V to both enable pins. Power-On Reset (POR) The power-on reset output is an open-drain N-Channel device, requiring a pull-up resistor to either the input voltage or output voltage for proper voltage levels. The POR output has a delay time that is programmable with a capacitor from the SET pin to ground. The delay time can be programmed to be as long as 1 second. The SET pin is a current source output that charges a capacitor that sets the delay time for the power-on reset output. The current source is a 1.25uA current source that charges a capacitor up from 0V. When the capacitor reaches 1.25V, the output of the POR is allowed to go high. The delay time in micro seconds is equal to the Cset in picofarads. POR Delay (s) = CSET (pF) LowQTM Mode The LowQTM pin is logic level low, requiring <0.2V to enter the LowQTM mode. The LowQTM pin cannot be left floating. Features of the LowQTM mode include lower total quiescent current of typically 7uA. LowQ Mode can be used in many portable electronics applications where long battery life is crucial. These include cell phones, mp3 players, digital cameras and PDAs. The lower ground current will increase the life of the battery and prolong the usage between charges.
Input Capacitor Good bypassing is recommended from input to ground to help improve AC performance. A 1F capacitor or greater located close to the IC is recommended. Larger load currents may require larger capacitor values. Bypass Capacitor The internal reference voltage of the MIC5312 can be bypassed with a capacitor to ground to reduce output noise and increase input ripple rejection (PSRR). A quick-start feature allows for quick turn-on of the output voltage. The recommended nominal bypass capacitor is 0.01F, but an increase will result in longer turn on times ton. Output Capacitor Each regulator output requires a 2.2F ceramic output capacitor for stability. The output capacitor value can be increased to improve transient response, but performance has been optimized for a 2.2F ceramic type output capacitor. X7R/X5R dielectric-type ceramic capacitors are recommended because of their temperature performance. X7R-type 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% to 60% respectively over their operating temperature ranges. To use a ceramic chip capacitor with Y5V dielectric, the value must be much higher than a X7R ceramic capacitor to ensure the same minimum capacitance over the equivalent operating temperature range. Thermal Considerations The MIC5312 is designed to provide 300mA of continuous current per channel in a very small MLF package. Maximum power dissipation can be calculated based on the output current and the voltage drop across the part. To determine the maximum power dissipation of the package, use the junction-to-ambient thermal resistance of the device and the following basic equation: PD (max) = (TJ (max) - TA) /JA TJ (max) is the maximum junction temperature of the die, 125C, and TA is the ambient operating temperature. JA is layout dependent; Table 1 shows examples of the junction-to-ambient thermal resistance for the MIC5312. Package 3x3 MLFTM-10 JA Recommended Minimum Footprint 63C/W JC 2C/W
Table 1. MLFTM Thermal Resistance
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Micrel, Inc. The actual power dissipation of the regulator circuit can be determined using the equation: PDTOTAL = PD LDO1 + PD LDO2 PD LDO1 = (VIN-VOUT1) x IOUT1 PD LDO2 = (VIN-VOUT2) x IOUT2 Substituting PD(max) for PD and solving for the operating conditions that are critical to the application will give the maximum operating conditions for the regulator circuit. For example, when operating the MIC5312 at 60C with a minimum footprint layout, the maximum load currents can be calculated as follows: PD (max) = (TJ (max) - TA) /JA PD (max) = (125C - 60C) / 63C /W PD (max) = 1.03W The junction-to-ambient thermal resistance for the minimum footprint is 63C/W, from Table 1. The maximum power dissipation must not be exceeded for proper operation. Using a lithium-ion battery as the supply voltage of 4.2V, 1.8VOUT/150mA for channel 1 and 2.8VOUT/100mA for channel 2, power dissipation can be calculated as follows: PD LDO1 = (VIN-VOUT1) x IOUT1 PD LDO1 = (4.2V-1.8V) x 150mA PD LDO1 = 360mW
MIC5312 PD LDO2 = (VIN-VOUT2) x IOUT2 PD LDO1 = (4.2V-2.8V) x 100mA PD LDO1 = 140mW PDTOTAL = PD LDO1 + PD LDO2 PDTOTAL = 360mW + 140mW PDTOTAL = 500mW The calculation shows that we are well below the maximum allowable power dissipation of 1.03W for a 60 ambient temperature. After the maximum power dissipation has been calculated, it is always a good idea to calculate the maximum ambient temperature for a 125 junction temperature. Calculating maximum ambient temperature as follows: TA(max) = TJ(max) - (PD x JA) TA(max) = 125C - (500mW x 63C/W) TA(max) = 93.5C For a full discussion of heat sinking and thermal effects on voltage regulators, refer to the "Regulator Thermals" section of Micrel's Designing with Low-Dropout Voltage Regulators handbook. This information can be found on Micrel's website at: http://www.micrel.com/_PDF/other/LDOBk_ds.pdf
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MIC5312
Package Information
10-Pin 3x3 MLF (MLF)
MICREL, INC. 2180 FORTUNE DRIVE SAN JOSE, CA 95131 USA
TEL +1 (408) 944-0800 FAX +1 (408) 474-1000 WEB http:/www.micrel.com
The information furnished by Micrel in this data sheet 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 a Purchaser's own risk and Purchaser agrees to fully indemnify Micrel for any damages resulting from such use or sale. (c) 2004 Micrel, Incorporated.
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