MIC5357 High Performance, Low Noise Dual 500mA ULDO™ General Description Features The MIC5357 is a tiny Dual Ultra Low Dropout (ULDO™) linear regulator ideally suited for portable electronics due to its low output noise. The MIC5357 provides two independently controlled high performance 500mA LDOs with typical dropout voltage of 130mV at rated load. In addition, the MIC5357 provides a bypass pin to reduce the output noise. The MIC5357 is designed to be stable with small ceramic output capacitors thereby reducing required board space and component cost. The combination of extremely low dropout voltage, low output noise and exceptional thermal package characteristics makes it ideal for powering RF and noise sensitive circuitry, cellular phone camera modules, imaging sensors for digital still cameras, PDAs, MP3 players and WebCam applications. The MIC5357 ULDO™ is available in fixed output voltages in the small 8-pin ePad MSOP package. Additional voltage options are available. For more information, contact Micrel marketing. Data sheets and support documentation can be found on Micrel’s web site at: www.micrel.com. • • • • • • • • • • 2.6V to 5.5V input voltage range Ultra low dropout voltage: 130mV @ 500mA Ultra low output noise: 51µVRMS ±2% initial output accuracy Small 8-pin ePad MSOP package Excellent Load/Line transient response Fast start up time: 38µs µCap stable with 2.2µF ceramic capacitors Thermal shutdown protection Low quiescent current: 160µA with both outputs at maximum load • Current-limit protection Applications • • • • • • Battery-Powered Applications PDAs GPS receivers Portable electronics Portable media players Digital still and video cameras _________________________________________________________________________________________________________________________ Typical Application RF Power Supply Circuit ULDO is a trademark of Micrel, 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 January 2011 M9999-011311 Micrel, Inc. MIC5357 Block Diagram January 2011 2 M9999-011311 Micrel, Inc. MIC5357 Ordering Information Part Number (1) Manufacturing Part Number Marking MIC5357-3.3/2.8YMME MIC5357-SMYMME MIC5357-3.3/1.8YMME Voltage(V) VOUT1 VOUT2 Junction Temperature Range 57SM 3.3V 2.8V –40°C to +125°C 8-Pin ePAD MSOP MIC5357-SGYMME 57SG 3.3V 1.8V –40°C to +125°C 8-Pin ePAD MSOP MIC5357-2.8/1.8YMME MIC5357-MGYMME 57MG 2.8V 1.8V –40°C to +125°C 8-Pin ePAD MSOP MIC5357-1.8/1.5YMME MIC5357-GFYMME 57GF 1.8V 1.5V –40°C to +125°C 8-Pin ePAD MSOP Package Notes 1. For other voltage options contact Micrel Marketing. Pin Configuration 8-Pin ePAD MSOP (MME) TOP VIEW Pin Description Pin Number Pin Name Pin Function 1 VIN Supply Input. 2 GND Ground. 3 BYP Reference Bypass: Connect external 0.1µF to GND to reduce output noise. May be left open when bypass capacitor is not required. 4 EN2 Enable Input (regulator 2). Active High Input. Logic High = On; Logic Low = Off; Do not leave floating. 5 EN1 Enable Input (regulator 1). Active High Input. Logic High = On; Logic Low = Off; Do not leave floating. 6 NC Not internally connected. 7 VOUT2 Regulator Output – LDO2. 8 VOUT1 Regulator Output – LDO1. ePAD HS Pad Heatsink Pad internally connected to ground. January 2011 3 M9999-011311 Micrel, Inc. MIC5357 Absolute Maximum Ratings(1) Operating Ratings(2) Supply Voltage (VIN) ........................................ −0.3V to +6V Enable Input Voltage (VEN1 , VEN2).....................−0.3V to VIN Power Dissipation ..................................Internally Limited(3) Lead Temperature (soldering, 3sec) .......................... 260°C Storage Temperature (TS).........................−65°C to +150°C ESD Rating(4) ................................................................. 2kV Supply Voltage (VIN)..................................... +2.6V to +5.5V Enable Input Voltage (VEN1, VEN2) .......................... 0V to VIN Junction Temperature ............................... –40°C to +125°C Junction Thermal Resistance 8-Pin ePAD MSOP (θJA) .................................64.4°C/W Electrical Characteristics(5) VIN = VEN1 = VEN2 = VOUT + 1.0V; higher of the two regulator outputs, IOUTLDO1 = IOUTLDO2 = 100µA; COUT1 = COUT2 = 2.2µF; CBYP = 0.1µF; TJ = 25°C, bold values indicate –40°C ≤ TJ ≤ +125°C, unless noted. Parameter Output Voltage Accuracy Conditions Min. Typ. Max. Variation from nominal VOUT -2.0 +2.0 Variation from nominal VOUT; –40°C to +125°C -3.0 +3.0 Units % Line Regulation VIN = VOUT + 1V to 5.5V; IOUT = 100µA 0.05 0.3 0.6 %/V Load Regulation IOUT1&2 =100µA to 500mA 0.7 2.5 % IOUT1,2 = 100µA 0.1 IOUT1,2 = 50mA 12 50 mV IOUT1,2 = 500mA 130 300 VEN1 ≥ 1.2V; VEN2 ≤ 0.2V; IOUT = 0mA to 500mA 95 175 VEN1 ≤ 0.2V; VEN2 ≥ 1.2V; IOUT2 = 0mA to 500mA 95 175 VEN1 = VEN2 ≥ 1.2V; IOUT1 = 500mA, IOUT2 = 500mA 160 240 VEN1 = VEN2 = 0V 0.01 2 Dropout Voltage (6) Ground Current Ground Current in Shutdown Ripple Rejection Current Limit Output Voltage Noise f = 1kHz; COUT = 2.2µF; CBYP = 0.1µF 70 f = 20kHz; COUT = 2.2µF; CBYP = 0.1µF 45 µA dB VOUT1 = 0V 550 950 1300 VOUT2 = 0V 550 950 1300 COUT = 2.2µF; CBYP = 0.1µF; 10Hz to 100kHz µA 51 mA µVRMS Enable Inputs (EN1 / EN2) Enable Input Voltage Enable Input Current 0.2 Logic Low 1.2 Logic High VIL ≤ 0.2V 0.01 VIH ≥ 1.2V 0.01 V µA Turn-on Time (See Timing Diagram) Turn-on Time (LDO1 and 2) COUT = 2.2µF; CBYP = 0.1µF 38 100 µs 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) / θJA. Exceeding the maximum allowable power dissipation will result in excessive die temperature, and the regulator will go into thermal shutdown. 4. Devices are ESD sensitive. Handling precautions recommended. Human body model 1.5kΩ in series with 100pF. 5. Specification for packaged product only. 6. Dropout voltage is defined as the input-to-output differential at which the output voltage drops 2% below its nominal VOUT. For outputs below 2.6V, the dropout voltage is the input-to-output differential with the minimum input voltage 2.6V. January 2011 4 M9999-011311 Micrel, Inc. MIC5357 Typical Characteristics Ground Current vs. Output Current (VOUT1) Ground Current vs. Output Current (VOUT2) 100 100 Ground Current vs. Temperature(Dual Outputs) 180 IOUT1=500mA , IOUT2=500mA 95 90 VIN =4.3V 85 VOUT1=3.3V GROUND CURRENT (μA) GROUND CURRENT (μA) GROUND CURRENT (μA) 170 95 90 VIN =4.3V 85 VOUT2=2.8V 150 140 130 120 110 IOUT1=500mA 100 90 80 CIN =COUT=2.2μF CIN =COUT=2.2μF 160 70 80 -40 -20 80 0 50 100 150 200 250 300 350 400 450 500 0 OUTPUT CURRENT (mA) Output Voltage vs. Input Voltage 3.1 3 500mA VOUT1=3.3V 100μA 2.8 2.7 500mA 2.6 VOUT2=2.8V CIN =COUT=2.2μF 2.6 OUTPUT VOLTAGE (V) 3.2 2.7 2.9 OUTPUT VOLTAGE (V) OUTPUT VOLTAGE (V) 100μA 2.8 CIN =COUT=2.2μF 3.5 3.4 3 3.5 4 4.5 80 100 120 5 3.2 3.1 V IN =4.3V CIN =COUT=2.2μF 3 2.9 V OUT2 2.8 2.7 2.6 2.5 0 2.5 5.5 VOUT1 3.3 2.5 2.5 2.5 60 3.6 3.5 2.9 40 Output Voltage vs. Output Current 3 3.6 3.3 20 TEMPERATURE (°C) OUTPUT CURRENT (mA) Output Voltage vs. Input Voltage 3.4 0 50 100 150 200 250 300 350 400 450 500 3 3.5 4 4.5 INPUT VOLTAGE (V) INPUT VOLTAGE (V) Dropout Voltage vs. Temperature Dropout Voltage vs. Output Current 5 5.5 100 200 300 400 500 OUTPUT CURRENT (mA) Current Limit vs. Input Voltage 1200 CIN =COUT=2.2μF 120 500mA 105 300mA 90 75 150mA 60 45 30 50mA 15 105 90 75 60 ` 45 30 VOUT1=3.3V 15 -40 -20 0 20 40 60 80 100 0 120 100 TEMPERATURE (°C) 100µA NOISE (uV/√Hz) dB -50 -40 -30 VEN1=VIN =4.74V -10 V OUT1=3.3V COUT1=2.2µF 0.1 0.01 0.001 0 100 1000 10000 FREQUENCY(Hz) January 2011 CIN =COUT=2.2μF 500 2.5 3 3.5 4 4.5 5 5.5 INPUT VOLTAGE (V) 100000 V IN=4.7V V OUT2=1.8V CBY P=0.1µA 10 900 1 -60 -20 VOUT1=3.3V 950 10 300mA 500mA -70 400 1000 Output Noise Spectral Density 150mA -80 300 1050 800 OUTPUT CURRENT (mA) Power Supply Rejection Ratio -90 200 1100 850 CIN =COUT=2.2μF 0 0 VOUT2=2.8V 1150 120 CURRENT LIMIT (mA) DROPOUT VOLTAGE (mV) 135 DROPOUT VOLTAGE (mV) 150 CIN-COUT=2.2µF/6.3V IL=250mA Noise Output (10Hz to 100Khz)=51.16µVrms 10 100 1000 10000 100000 1000000 FREQUENCY (Hz) 5 M9999-011311 Micrel, Inc. MIC5357 Functional Characteristics January 2011 6 M9999-011311 Micrel, Inc. MIC5357 A unique, quick start circuit allows the MIC5357 to drive a large capacitor on the bypass pin without significantly slowing the turn on time. Applications Information Enable/Shutdown The MIC5357 is provided with dual active high enable pins that allow each regulator to be enabled independently. Forcing both enable pins low disables the regulators 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. The active high enable pin uses CMOS technology and the enable pin cannot be left floating; a floating enable pin may cause an indeterminate state on the output. No-Load Stability Unlike many other voltage regulators, the MIC5357 will remain stable with no load. This is especially important in CMOS RAM keep alive applications. Thermal Considerations The MIC5357 is designed to provide 500mA of continuous current for VOUT1 and 500mA for VOUT2 in a small package. The maximum ambient operating temperature can be calculated based on the output current and the voltage drop across the part. Given that the input voltage is 3.6V, the output voltage is 3.3V for VOUT1, 2.8V for VOUT2 and the output current of 500mA and 500mA respectively. The actual power dissipation of the regulator circuit can be determined using the equation: Input Capacitor The MIC5357 is a high performance, high bandwidth device. Therefore, it requires a well bypassed input supply for optimal performance. A 2.2µF 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. PD = (VIN – VOUT1) IOUT1 + (VIN – VOUT2) IOUT2+ VIN IGND Because this device is CMOS and the ground current is typically <100µA over the load range, the power dissipation contributed by the ground current is < 1% and can be ignored for this calculation. Output Capacitor The MIC5357 requires an output capacitor of 2.2µF or greater to maintain stability. The design is optimized for use with low ESR ceramic chip capacitors. High ESR capacitors may cause high frequency oscillation. The output capacitor can be increased, but performance has been optimized for a 2.2µF ceramic output capacitor and does not improve significantly with larger capacitance. X7R/X5R dielectric type ceramic capacitors are recommended because of their superior 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% 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. PD = (3.6V – 3.3V) × 500mA + (3.6V -2.8) × 500mA PD = 0.55W To determine the maximum ambient operating temperature 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) = 125°C, the maximum junction temperature of the die θJA thermal resistance = 64.4°C/W. Bypass Capacitor A capacitor can be placed from the noise bypass pin to ground to reduce output voltage noise. The capacitor bypasses the internal reference. A 0.1µF capacitor is recommended for applications that require low noise outputs. The bypass capacitor can be increased, further reducing noise and improving PSRR. Turn on time increases slightly with respect to bypass capacitance. January 2011 7 M9999-011311 Micrel, Inc. MIC5357 Thermal Resistance Therefore, a 3.3V/2.8V application with 500mA and 500mA output currents can accept an ambient operating temperature of 89.6°C in a small 8 Pin ePAD MSOP package. 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 Substituting PD for PD(max) and solving for the ambient operating temperature will give the maximum operating conditions for the regulator circuit. The junction to ambient thermal resistance for the minimum footprint is 64.4°C/W. The maximum power dissipation must not be exceeded for proper operation. For example, when operating the MIC5357 at an input voltage of 3.6V and 500mA on VOUT1 and 500mA on VOUT2, the maximum ambient operating temperature TA can be determined as follows: 0.55W = (125°C – TA)/(64.4°C/W) TA = 89.6°C January 2011 8 M9999-011311 Micrel, Inc. MIC5357 Typical Application Schematic Bill of Materials Item C1, C2,C3 C4 U1 Part Number Manufacturer C1005X5R0J225M TDK(1) VJ0402Y104KXX MIC5357-xxYMME (2) Vishay Micrel, Inc. (3) Description Qty. Capacitor, 2.2µF Ceramic, 6.3V, X5R, Size 0402 3 Capacitor, 0.1µF Ceramic, 25V, X7R, Size 0402 1 High Performance, Low Noise Dual 500mA ULDO™ 1 Notes: 1. TDK: www.tdk.com. 2. Vishay Tel: www.vishay.com. 3. Micrel, Inc.: www.micrel.com. January 2011 9 M9999-011311 Micrel, Inc. MIC5357 PCB Layout Recommendations Top Layer Bottom Layer January 2011 10 M9999-011311 Micrel, Inc. MIC5357 Package Information 8-Pin ePAD MSOP (MME) 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 Micrel makes no representations or warranties with respect to the accuracy or completeness of the information furnished in this data sheet. This information is not intended as a warranty and Micrel does not assume responsibility for its use. Micrel reserves the right to change circuitry, specifications and descriptions at any time without notice. No license, whether express, implied, arising by estoppel or otherwise, to any intellectual property rights is granted by this document. Except as provided in Micrel’s terms and conditions of sale for such products, Micrel assumes no liability whatsoever, and Micrel disclaims any express or implied warranty relating to the sale and/or use of Micrel products including liability or warranties relating to fitness for a particular purpose, merchantability, or infringement of any patent, copyright or other intellectual property right. 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. © 2011 Micrel, Incorporated. January 2011 11 M9999-011311