MIC5321 Dual, High Performance 150mA Cap ULDOTM General Description Features The MIC5321 is a tiny Dual Ultra Low-Dropout (ULDOTM) linear regulator ideally suited for those applications that require high PSRR because it provides a bypass pin for those noise sensitive portable electronics. The MIC5321 integrates two high-performance; 150mA ULDOs into a very compact 1.6mm x 1.6mm leadless MLF (R) package that provides exceptional thermal package characteristics. The MIC5321 is a Cap design which enables operation with very small ceramic output capacitors for stability, thereby reducing required board space and component cost. The combination of extremely low-drop-out voltage, very high power supply rejection, very low output noise and exceptional thermal package characteristics makes it ideal for powering RF application, cellular phone camera modules, imaging sensors for digital still cameras, PDAs, MP3 players and WebCam applications. The MIC5321 ULDOTM is available in fixed-output voltages in the tiny 6-pin 1.6mm x 1.6mm leadless MLF (R) package which is only 2.56mm2 in area, less than 30% the area of the SOT-23, TSOP and MLF 3x3 packages. It's also available in the thin SOT-23-6 lead package. Additional voltage options are available. For more information, contact Micrel marketing department. * * * * * * * * * * * * 2.3V to 5.5V input voltage range Ultra-low dropout voltage ULDOTM 35mV @ 150mA Tiny 6-pin 1.6mm x 1.6mm MLF(R) leadless package Low cost TSOT-23-6 package Bypass pin for improved noise performance High PSRR - >75dB on each LDO Ultra low noise output - > 30Vrms Dual 150mA outputs Cap stable with 1F ceramic capacitor Low quiescent current - 150A Fast turn-on time - 45s Thermal shutdown protection Current Limit protection Applications * * * * * * Data sheets and support documentation can be found on Micrel's web site at www.micrel.com. Mobile phones PDAs GPS receivers Portable electronics Portable media players Digital still and video cameras Typical Application MIC5321-x.xYML VIN 1F VOUT 1 Rx/Synth VOUT 2 Tx EN BYP GND 1F 1F RF Transceiver 0.01F RF Power Supply Circuit ULDO is a trademark of Micrel, Inc. MLF and MicroLeadFrame are registered 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 July 2006 M9999-073106 Micrel, Inc. MIC5321 Ordering Information Part number MIC5321-1.8/1.5YML MIC5321-1.8/1.6YML MIC5321-2.5/1.8YML MIC5321-2.5/2.5YML MIC5321-2.6/1.85YML MIC5321-2.6/1.8YML MIC5321-2.7/2.7YML MIC5321-2.8/1.5YML MIC5321-2.8/1.8YML MIC5321-2.8/2.6YML MIC5321-2.8/2.8YML MIC5321-2.8/2.85YML MIC5321-2.85/1.85YML MIC5321-2.85/2.6YML MIC5321-2.85/2.85YML MIC5321-2.85/2.85YML MIC5321-2.9/1.5YML MIC5321-2.9/1.8YML MIC5321-2.9/2.9YML MIC5321-3.0/1.8YML MIC5321-3.0/2.5YML MIC5321-3.0/2.6YML MIC5321-3.0/2.8YML MIC5321-3.0/2.85YML MIC5321-3.0/3.0YML MIC5321-3.3/1.5YML MIC5321-3.3/1.8YML MIC5321-3.3/2.5YML MIC5321-3.3/2.6YML MIC5321-3.3/2.7YML MIC5321-3.3/2.8YML MIC5321-3.3/2.85YML MIC5321-3.3/2.9YML MIC5321-3.3/3.0YML MIC5321-3.3/3.2YML MIC5321-3.3/3.3YML MIC5321-1.8/1.5YD6 MIC5321-1.8/1.6YD6 MIC5321-2.5/1.8YD6 MIC5321-2.5/2.5YD6 MIC5321-2.6/1.85YD6 MIC5321-2.6/1.8YD6 MIC5321-2.7/2.7YD6 MIC5321-2.8/1.5YD6 MIC5321-2.8/1.8YD6 MIC5321-2.8/2.6YD6 July 2006 Manufacturing Part Number MIC5321-GFYML MIC5321-GWYML MIC5321-JGYML MIC5321-JJYML MIC5321-KDYML MIC5321-KGYML MIC5321-LLYML MIC5321-MFYML MIC5321-MGYML MIC5321-MKYML MIC5321-MMYML MIC5321-MNYML MIC5321-NDYML MIC5321-NKYML MIC5321-NNYML MIC5321-NNYML MIC5321-OFYML MIC5321-OGYML MIC5321-OOYML MIC5321-PGYML MIC5321-PJYML MIC5321-PKYML MIC5321-PMYML MIC5321-PNYML MIC5321-PPYML MIC5321-SFYML MIC5321-SGYML MIC5321-SJYML MIC5321-SKYML MIC5321-SLYML MIC5321-SMYML MIC5321-SNYML MIC5321-SOYML MIC5321-SPYML MIC5321-SRYML MIC5321-SSYML MIC5321-GFYD6 MIC5321-GWYD6 MIC5321-JGYD6 MIC5321-JJYD6 MIC5321-KDYD6 MIC5321-KGYD6 MIC5321-LLYD6 MIC5321-MFYD6 MIC5321-MGYD6 MIC5321-MKYD6 Voltage 1.8V/1.5V 1.8V/1.6V 2.5V/1.8V 2.5V/2.5V 2.6V/1.85 2.6V/1.8V 2.7V/2.7V 2.8V/1.5V 2.8V/1.8V 2.8V/2.6V 2.8V/2.8V 2.8V/2.85V 2.85V/1.85V 2.85V/2.6V 2.85V/2.85V 2.85V/2.85V 2.9V/1.5V 2.9V/1.8V 2.9V/2.9V 3.0V/1.8V 3.0V/2.5V 3.0V/2.6V 3.0V/2.8V 3.0V/2.85V 3.0V/3.0V 3.3V/1.5V 3.3V/1.8V 3.3V/2.5V 3.3V/2.6V 3.3V/2.7V 3.3V/2.8V 3.3V/2.85V 3.3V/2.9V 3.3V/3.0V 3.3V/3.2V 3.3V/3.3V 1.8V/1.5V 1.8V/1.6V 2.5V/1.8V 2.5V/2.5V 2.6V/1.85 2.6V/1.8V 2.7V/2.7V 2.8V/1.5V 2.8V/1.8V 2.8V/2.6V 2 Junction Temperature Range -40C to +125C -40C to +125C -40C to +125C -40C to +125C -40C to +125C -40C to +125C -40C to +125C -40C to +125C -40C to +125C -40C to +125C -40C to +125C -40C to +125C -40C to +125C -40C to +125C -40C to +125C -40C to +125C -40C to +125C -40C to +125C -40C to +125C -40C to +125C -40C to +125C -40C to +125C -40C to +125C -40C to +125C -40C to +125C -40C to +125C -40C to +125C -40C to +125C -40C to +125C -40C to +125C -40C to +125C -40C to +125C -40C to +125C -40C to +125C -40C to +125C -40C to +125C -40C to +125C -40C to +125C -40C to +125C -40C to +125C -40C to +125C -40C to +125C -40C to +125C -40C to +125C -40C to +125C -40C to +125C Package 6-Pin 1.6x1.6 MLF(R) 6-Pin 1.6x1.6 MLF(R) 6-Pin 1.6x1.6 MLF(R) 6-Pin 1.6x1.6 MLF(R) 6-Pin 1.6x1.6 MLF(R) 6-Pin 1.6x1.6 MLF(R) 6-Pin 1.6x1.6 MLF(R) 6-Pin 1.6x1.6 MLF(R) 6-Pin 1.6x1.6 MLF(R) 6-Pin 1.6x1.6 MLF(R) 6-Pin 1.6x1.6 MLF(R) 6-Pin 1.6x1.6 MLF(R) 6-Pin 1.6x1.6 MLF(R) 6-Pin 1.6x1.6 MLF(R) 6-Pin 1.6x1.6 MLF(R) 6-Pin 1.6x1.6 MLF(R) 6-Pin 1.6x1.6 MLF(R) 6-Pin 1.6x1.6 MLF(R) 6-Pin 1.6x1.6 MLF(R) 6-Pin 1.6x1.6 MLF(R) 6-Pin 1.6x1.6 MLF(R) 6-Pin 1.6x1.6 MLF(R) 6-Pin 1.6x1.6 MLF(R) 6-Pin 1.6x1.6 MLF(R) 6-Pin 1.6x1.6 MLF(R) 6-Pin 1.6x1.6 MLF(R) 6-Pin 1.6x1.6 MLF(R) 6-Pin 1.6x1.6 MLF(R) 6-Pin 1.6x1.6 MLF(R) 6-Pin 1.6x1.6 MLF(R) 6-Pin 1.6x1.6 MLF(R) 6-Pin 1.6x1.6 MLF(R) 6-Pin 1.6x1.6 MLF(R) 6-Pin 1.6x1.6 MLF(R) 6-Pin 1.6x1.6 MLF(R) 6-Pin 1.6x1.6 MLF(R) 6-Pin TSOT-23 6-Pin TSOT-23 6-Pin TSOT-23 6-Pin TSOT-23 6-Pin TSOT-23 6-Pin TSOT-23 6-Pin TSOT-23 6-Pin TSOT-23 6-Pin TSOT-23 6-Pin TSOT-23 M9999-073106 Micrel, Inc. MIC5321-2.8/2.8YD6 MIC5321-2.8/2.85YD6 MIC5321-2.85/1.85YD6 MIC5321-2.85/2.6YD6 MIC5321-2.85/2.85YD6 MIC5321-2.9/1.5YD6 MIC5321-2.9/1.8YD6 MIC5321-2.9/2.9YD6 MIC5321-3.0/1.8YD6 MIC5321-3.0/2.5YD6 MIC5321-3.0/2.6YD6 MIC5321-3.0/2.8YD6 MIC5321-3.0/2.85YD6 MIC5321-3.0/3.0YD6 MIC5321-3.3/1.5YD6 MIC5321-3.3/1.8YD6 MIC5321-3.3/2.5YD6 MIC5321-3.3/2.6YD6 MIC5321-3.3/2.7YD6 MIC5321-3.3/2.8YD6 MIC5321-3.3/2.85YD6 MIC5321-3.3/2.9YD6 MIC5321-3.3/3.0YD6 MIC5321-3.3/3.2YD6 MIC5321-3.3/3.3YD6 MIC5321 MIC5321-MMYD6 MIC5321-MNYD6 MIC5321-NDYD6 MIC5321-NKYD6 MIC5321-NNYD6 MIC5321-OFYD6 MIC5321-OGYD6 MIC5321-OOYD6 MIC5321-PGYD6 MIC5321-PJYD6 MIC5321-PKYD6 MIC5321-PMYD6 MIC5321-PNYD6 MIC5321-PPYD6 MIC5321-SFYD6 MIC5321-SGYD6 MIC5321-SJYD6 MIC5321-SKYD6 MIC5321-SLYD6 MIC5321-SMYD6 MIC5321-SNYD6 MIC5321-SOYD6 MIC5321-SPYD6 MIC5321-SRYD6 MIC5321-SSYD6 2.8V/2.8V 2.8V/2.85V 2.85V/1.85V 2.85V/2.6V 2.85V/2.85V 2.9V/1.5V 2.9V/1.8V 2.9V/2.9V 3.0V/1.8V 3.0V/2.5V 3.0V/2.6V 3.0V/2.8V 3.0V/2.85V 3.0V/3.0V 3.3V/1.5V 3.3V/1.8V 3.3V/2.5V 3.3V/2.6V 3.3V/2.7V 3.3V/2.8V 3.3V/2.85V 3.3V/2.9V 3.3V/3.0V 3.3V/3.2V 3.3V/3.3V -40C to +125C -40C to +125C -40C to +125C -40C to +125C -40C to +125C -40C to +125C -40C to +125C -40C to +125C -40C to +125C -40C to +125C -40C to +125C -40C to +125C -40C to +125C -40C to +125C -40C to +125C -40C to +125C -40C to +125C -40C to +125C -40C to +125C -40C to +125C -40C to +125C -40C to +125C -40C to +125C -40C to +125C -40C to +125C 6-Pin TSOT-23 6-Pin TSOT-23 6-Pin TSOT-23 6-Pin TSOT-23 6-Pin TSOT-23 6-Pin TSOT-23 6-Pin TSOT-23 6-Pin TSOT-23 6-Pin TSOT-23 6-Pin TSOT-23 6-Pin TSOT-23 6-Pin TSOT-23 6-Pin TSOT-23 6-Pin TSOT-23 6-Pin TSOT-23 6-Pin TSOT-23 6-Pin TSOT-23 6-Pin TSOT-23 6-Pin TSOT-23 6-Pin TSOT-23 6-Pin TSOT-23 6-Pin TSOT-23 6-Pin TSOT-23 6-Pin TSOT-23 6-Pin TSOT-23 Note: 1. Other Voltages available. Contact Micrel for details. July 2006 3 M9999-073106 Micrel, Inc. MIC5321 Pin Configuration VIN 1 6 VOUT1 GND 2 5 VOUT2 BYP 3 4 EN VIN GND BYP 3 2 1 4 5 6 VOUT1 VOUT2 6-Pin 1.6mm x 1.6mm MLF (ML) Top View EN TSOT-23-6 (D6) Top View Pin Description Pin Number MLF-6 Pin Number TSOT-23-6 Pin Name Pin Function 1 3 VIN Supply Input. 2 2 GND Ground 3 1 BYP Reference Bypass: Connect external 0.01F to GND to reduce output noise. May be left open. 4 6 EN 5 5 VOUT2 Regulator Output - LDO2 6 4 VOUT1 Regulator Output - LDO1 July 2006 Enable Input (both regulators): Active High Input. Logic High = On; Logic Low = Off; Do not leave floating. 4 M9999-073106 Micrel, Inc. MIC5321 Absolute Maximum Ratings(1) Operating Ratings(2) Supply Voltage (VIN) .....................................0V to +6V Enable Input Voltage (VEN)...........................0V to +6V Power Dissipation......................Internally Limited(3) Lead Temperature (soldering, 3sec) ..................260C Storage Temperature (TS) ................ -65C to +150C ESD Rating(4) .........................................................2kV Supply Voltage (VIN).............................. +2.3V to +5.5V Enable Input Voltage (VEN).............................. 0V to VIN Junction Temperature (TJ) ................. -40C to +125C Junction Thermal Resistance MLF-6 (JA) ............................................. 100C/W TSOT-6 (JA) ........................................... 235C/W Electrical Characteristics(5) VIN = EN = VOUT + 1.0V; higher of the two regulator outputs, IOUTLDO1 = IOUTLDO2 = 100A; COUT1 = COUT2 = 1F; CBYP = 0.01F; TJ = 25C, bold values indicate -40C TJ +125C, unless noted. Parameter Conditions Output Voltage Accuracy Min Typ Max Units Variation from nominal VOUT -2.0 +2.0 % Variation from nominal VOUT; -40C to +125C -3.0 +3.0 % VIN = VOUT + 1V to 5.5V; IOUT = 100A 0.02 0.3 0.6 %/V %/V IOUT = 100A to 150mA 0.5 2.0 % IOUT = 100A 0.1 IOUT = 50mA 12 IOUT = 100mA IOUT = 150mA Ground Current Line Regulation Load Regulation Dropout Voltage (6) mV 50 mV 25 75 mV 35 100 mV EN = High; IOUT1 = 150mA, IOUT2 = 150mA 150 190 A Ground Current in Shutdown EN1 0.2V 0.01 2 A Ripple Rejection f = 1kHz; COUT = 1.0F; CBYP = 0.1F 75 dB f = 20kHz; COUT = 1.0F; CBYP = 0.1F 45 dB 300 Current Limit VOUT = 0V Output Voltage Noise COUT = 1.0F; CBYP = 0.01F; 10Hz to 100kHz 550 950 30 mA VRMS Enable Inputs (EN) Enable Input Voltage 0.2 Logic Low 1.1 Logic High Enable Input Current V V VIL 0.2V 0.01 1 A VIH 1.0V 0.01 1 A COUT = 1.0F; No CBYP 40 100 s COUT = 1.0F; CBYP = 0.01F 45 100 s Turn-on Time (See Timing Diagram) Turn-on Time (LDO1 and 2) 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. Devices are ESD sensitive. Handling precautions recommended. Human body model, 1.5k 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 it's nominal VOUT. For outputs below 2.3V, the dropout voltage is the input-to-output differential with the minimum input voltage 2.3V July 2006 5 M9999-073106 Micrel, Inc. MIC5321 Functional Diagram VIN VOUT 1 LDO1 LDO2 VOUT 2 EN Enable BYP Reference GND MIC5321 Block Diagram July 2006 6 M9999-073106 Micrel, Inc. MIC5321 Typical Characteristics -90 Power Supply Rejection Ratio 40 -80 35 -70 30 -60 50mA -40 V =V +1V 150mA -20 VIN =OUT OUT 2.8V -10 COUT = 1F CBYP = 0.1F 0 0.1 1 10 100 1,000 FREQUENCY (kHz) 20 Ground Current vs. Temperature 10 5 0 0 160 155 155 150 150 100A 145 140 140 135 135 130 125 120 VIN = VOUT + 1V VOUT = 3V COUT = 1F EN = VIN 20 40 60 80 TEMPERATURE (C) Dropout Voltage vs. Temperature 50 VIN = VOUT + 1V 45 VOUT = 2.8V C 40 OUT = 1F 35 30 25 20 15 10 5 0 162 100A 20 40 60 80 TEMPERATURE (C) Ground Current vs. Output Current 150 138 0 July 2006 2.90 Ground Current vs. Temperature 2.55 2.50 3.0 2.5 150mA VIN = VOUT + 1V VOUT = 2.8V COUT = 1F EN = VIN 20 40 60 80 TEMPERATURE (C) Output Voltage vs. Input Voltage 2.8V 2.0 1.5 VIN = VOUT + 1V VOUT = 3V COUT = 1F EN = VIN 20 40 60 80 TEMPERATURE (C) Output Voltage vs. Output Current 1.5V 1.0 0.5 0.0 0 1.60 IOUT = 100A COUT = 1F 1 2 3 4 5 6 INPUT VOLTAGE (V) Output Voltage vs. Output Current 2.85 1.55 2.80 1.50 2.75 VIN = VOUT + 1V VOUT = 2.8V COUT1 = COUT2 = 1F EN = VIN 2.70 0 25 50 75 100 125 150 OUTPUT CURRENT (mA) 1.45 VIN = VOUT + 1V VOUT = 1.5V COUT1 = COUT2 = 1F EN = VIN 1.40 0 25 50 75 100 125 150 OUTPUT CURRENT (mA) 610 600 Current Limit vs. Input Voltage 10 590 580 570 560 154 142 120 25 50 75 100 125 150 OUTPUT CURRENT (mA) 2.70 2.65 2.60 100mA 158 146 125 VIN = VOUT + 1V VOUT = 2.8V COUT = 1F EN = VIN 150mA 50mA 10mA 130 Output Voltage vs. Temperature 2.90 2.85 2.80 2.75 15 -30 145 3.00 2.95 25 -50 160 Dropout Voltage vs. Output Current VIN = VOUT + 1V VOUT = 2.85V EN = VIN COUT1 = COUT2 = 1F 25 50 75 100 125 150 OUTPUT CURRENT (mA) 1 0.1 550 540 530 520 510 3 Output Noise Spectral Density EN = VIN COUT = 1F 3.5 4 4.5 5 INPUT VOLTAGE (V) 7 5.5 0.01 VIN = 3.8V VOUT = 2.8V COUT = 1F CBYP = 0.01F 0.001 0.01 0.1 1 10 100 1,000 10,000 FREQUENCY (kHz) M9999-073106 Micrel, Inc. MIC5321 Functional Characteristics Enable Turn-On Enable (1V/div) Output Voltage (20mV/div) Load Transient 150mA VIN = VOUT + 1V VOUT = 2.8V VOUT1 (1V/div) COUT = 1F Output Current (50mA/div) CBYP = 0.1F VOUT2 (1V/div) VIN = VOUT + 1V VOUT1 = VOUT2 = 3.0V COUT = 1F CBYP = 0.1F 10mA Time (10s/div) Time (40s/div) Line Transient 5.5V Input Voltage (2V/div) 4V VIN = VOUT + 1V VOUT = 2.8V COUT = 1F Output Voltage (50mV/div) IOUT = 10mA Time (40s/div) July 2006 8 M9999-073106 Micrel, Inc. MIC5321 Applications Information increased, further reducing noise and improving PSRR. Turn-on time increases slightly with respect to bypass capacitance. A unique, quick-start circuit allows the MIC5321 to drive a large capacitor on the bypass pin without significantly slowing turn-on time. Refer to the Typical Characteristics section for performance with different bypass capacitors. Enable/Shutdown The MIC5321 comes with a single active-high enable pin that allows both regulators to be disabled simultaneously. Forcing the enable pin low disables the regulator and sends it into a "zero" off-modecurrent 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 MIC5321 will remain stable and in regulation with no load. This is especially important in CMOS RAM keep-alive applications. Input Capacitor The MIC5321 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 highfrequency capacitors, such as small-valued NPO dielectric-type capacitors, help filter out highfrequency noise and are good practice in any RFbased circuit. Thermal Considerations The MIC5321 is designed to provide 150mA of continuous current for both outputs in a very small package. 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 3.3V, the output voltage is 2.8V for VOUT1, 2.5V for VOUT2 and the output current = 150mA. The actual power dissipation of the regulator circuit can be determined using the equation: Output Capacitor The MIC5321 requires an output capacitor of 1F 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 1F ceramic output capacitor and does not improve significantly with larger capacitance. PD = (VIN - VOUT1) IOUT1 + (VIN - VOUT2) IOUT2+ VIN IGND Because this device is CMOS and the ground current is typically <150A over the load range, the power dissipation contributed by the ground current is < 1% and can be ignored for this calculation. PD = (3.3V - 2.8V) x 150mA + (3.3V -1.5) x 150mA PD = 0.345W 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% 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. To determine the maximum ambient operating temperature of the package, use the junction-toambient thermal resistance of the device and the following basic equation: PD(MAX) = TJ(MAX) - TA JA TJ(max) = 125C, the maximum junction temperature of the die JA thermal resistance = 100C/W. The table below shows junction-to-ambient thermal resistance for the MIC5321 in the MLF(R) package. 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 0.1F capacitor is recommended for applications that require low-noise outputs. The bypass capacitor can be July 2006 9 M9999-073106 Micrel, Inc. MIC5321 Package 6-Pin 1.6x1.6 MLF (R) JA Recommended Minimum Footprint JC 100C/W 2C/W For example, when operating the MIC5321-MFYML at an input voltage of 3.3V and 150mA loads at each output with a minimum footprint layout, the maximum ambient operating temperature TA can be determined as follows: 0.345W = (125C - TA)/(100C/W) Thermal Resistance 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 100C/W. The maximum power dissipation must not be exceeded for proper operation. TA=90.5C Therefore, a 2.8V/1.5V application with 150mA at each output current can accept an ambient operating temperature of 90.5C in a 1.6mm x 1.6mm MLF(R) 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 July 2006 10 M9999-073106 Micrel, Inc. MIC5321 Package Information 6-Pin 1.6mm x 1.5mm MLF (ML) 6-Pin TSOT-23 (D6) July 2006 11 M9999-073106 Micrel, Inc. MIC5321 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) 2005 Micrel, Inc. July 2006 12 M9999-073106