MIC5321 Dual, High Performance 150mA µCap ULDO™ General Description Features The MIC5321 is a tiny Dual Ultra Low-Dropout (ULDO™) 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 Thin MLF® package that provides exceptional thermal package characteristics. The MIC5321 is a µCap 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 ULDO™ is available in fixed-output voltages in the tiny 6-pin 1.6mm x 1.6mm leadless Thin MLF® 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 ULDO™ 35mV @ 150mA Tiny 6-pin 1.6mm x 1.6mm Thin MLF® leadless package Low cost TSOT-23-6 package Bypass pin for improved noise performance High PSRR – >75dB on each LDO Ultra low noise output - > 30µVrms Dual 150mA outputs µCap stable with 1µF ceramic capacitor Low quiescent current – 150µA Fast turn-on time – 45µs 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 1µF VOUT 1 Rx/Synth VOUT 2 Tx EN BYP GND 1µF 1µF RF Transceiver 0.01µF 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 January 2007 M9999-012407-C Micrel, Inc. MIC5321 Ordering Information Part number Manufacturing Part Number MIC5321-1.8/1.5YMT MIC5321-GFYMT MIC5321-1.8/1.6YMT Voltage Junction Temp. Range BGF 1.8V/1.5V –40°C to +125°C 6-Pin 1.6x1.6 Thin MLF® MIC5321-GWYMT BGW 1.8V/1.6V –40°C to +125°C 6-Pin 1.6x1.6 Thin MLF® MIC5321-2.5/1.8YMT MIC5321-JGYMT BJG 2.5V/1.8V –40°C to +125°C 6-Pin 1.6x1.6 Thin MLF® MIC5321-2.5/2.5YMT MIC5321-JJYMT BJJ 2.5V/2.5V –40°C to +125°C 6-Pin 1.6x1.6 Thin MLF® MIC5321-2.6/1.85YMT MIC5321-KDYMT BKD 2.6V/1.85 –40°C to +125°C 6-Pin 1.6x1.6 Thin MLF® MIC5321-2.6/1.8YMT MIC5321-KGYMT BKG 2.6V/1.8V –40°C to +125°C 6-Pin 1.6x1.6 Thin MLF® MIC5321-2.7/2.7YMT MIC5321-LLYMT BLL 2.7V/2.7V –40°C to +125°C 6-Pin 1.6x1.6 Thin MLF® MIC5321-2.8/1.5YMT MIC5321-MFYMT BMF 2.8V/1.5V –40°C to +125°C 6-Pin 1.6x1.6 Thin MLF® MIC5321-2.8/1.8YMT MIC5321-MGYMT BMG 2.8V/1.8V –40°C to +125°C 6-Pin 1.6x1.6 Thin MLF® MIC5321-2.8/2.6YMT MIC5321-MKYMT BMK 2.8V/2.6V –40°C to +125°C 6-Pin 1.6x1.6 Thin MLF® MIC5321-2.8/2.8YMT MIC5321-MMYMT BMM 2.8V/2.8V –40°C to +125°C 6-Pin 1.6x1.6 Thin MLF® MIC5321-2.8/2.85YMT MIC5321-MNYMT BMN 2.8V/2.85V –40°C to +125°C 6-Pin 1.6x1.6 Thin MLF® MIC5321-2.85/1.85YMT MIC5321-NDYMT BND 2.85V/1.85V –40°C to +125°C 6-Pin 1.6x1.6 Thin MLF® MIC5321-2.85/2.6YMT MIC5321-NKYMT BNK 2.85V/2.6V –40°C to +125°C 6-Pin 1.6x1.6 Thin MLF® MIC5321-2.85/2.85YMT MIC5321-NNYMT BNN 2.85V/2.85V –40°C to +125°C 6-Pin 1.6x1.6 Thin MLF® MIC5321-2.9/1.5YMT MIC5321-OFYMT BOF 2.9V/1.5V –40°C to +125°C 6-Pin 1.6x1.6 Thin MLF® MIC5321-2.9/1.8YMT MIC5321-OGYMT BOG 2.9V/1.8V –40°C to +125°C 6-Pin 1.6x1.6 Thin MLF® MIC5321-2.9/2.9YMT MIC5321-OOYMT BOO 2.9V/2.9V –40°C to +125°C 6-Pin 1.6x1.6 Thin MLF® MIC5321-3.0/1.8YMT MIC5321-PGYMT BPG 3.0V/1.8V –40°C to +125°C 6-Pin 1.6x1.6 Thin MLF® MIC5321-3.0/2.5YMT MIC5321-PJYMT BPJ 3.0V/2.5V –40°C to +125°C 6-Pin 1.6x1.6 Thin MLF® MIC5321-3.0/2.6YMT MIC5321-PKYMT BPK 3.0V/2.6V –40°C to +125°C 6-Pin 1.6x1.6 Thin MLF® MIC5321-3.0/2.8YMT MIC5321-PMYMT BPM 3.0V/2.8V –40°C to +125°C 6-Pin 1.6x1.6 Thin MLF® MIC5321-3.0/2.85YMT MIC5321-PNYMT BPN 3.0V/2.85V –40°C to +125°C 6-Pin 1.6x1.6 Thin MLF® MIC5321-3.0/3.0YMT MIC5321-PPYMT BPP 3.0V/3.0V –40°C to +125°C 6-Pin 1.6x1.6 Thin MLF® MIC5321-3.3/1.5YMT MIC5321-SFYMT BSF 3.3V/1.5V –40°C to +125°C 6-Pin 1.6x1.6 Thin MLF® MIC5321-3.3/1.8YMT MIC5321-SGYMT BSG 3.3V/1.8V –40°C to +125°C 6-Pin 1.6x1.6 Thin MLF® MIC5321-3.3/2.5YMT MIC5321-SJYMT BSJ 3.3V/2.5V –40°C to +125°C 6-Pin 1.6x1.6 Thin MLF MIC5321-3.3/2.6YMT MIC5321-SKYMT BSK 3.3V/2.6V –40°C to +125°C 6-Pin 1.6x1.6 Thin MLF® MIC5321-3.3/2.7YMT MIC5321-SLYMT BSL 3.3V/2.7V –40°C to +125°C 6-Pin 1.6x1.6 Thin MLF MIC5321-3.3/2.8YMT MIC5321-SMYMT BSM 3.3V/2.8V –40°C to +125°C 6-Pin 1.6x1.6 Thin MLF® MIC5321-3.3/2.85YMT MIC5321-SNYMT BSN 3.3V/2.85V –40°C to +125°C 6-Pin 1.6x1.6 Thin MLF® MIC5321-3.3/2.9YMT MIC5321-SOYMT BSO 3.3V/2.9V –40°C to +125°C 6-Pin 1.6x1.6 Thin MLF® MIC5321-3.3/3.0YMT MIC5321-SPYMT BSP 3.3V/3.0V –40°C to +125°C 6-Pin 1.6x1.6 Thin MLF® MIC5321-3.3/3.2YMT MIC5321-SRYMT BSR 3.3V/3.2V –40°C to +125°C 6-Pin 1.6x1.6 Thin MLF® MIC5321-3.3/3.3YMT MIC5321-SSYMT BSS 3.3V/3.3V –40°C to +125°C 6-Pin 1.6x1.6 Thin MLF® January 2007 Marking* 2 Package ® ® M9999-012407-C Micrel, Inc. Part number MIC5321 Marking* MIC5321-1.8/1.5YD6 Manufacturing Part Number MIC5321-GFYD6 Voltage QBGF MIC5321-1.8/1.6YD6 MIC5321-GWYD6 QBGW MIC5321-2.5/1.8YD6 MIC5321-JGYD6 MIC5321-2.5/2.5YD6 MIC5321-JJYD6 MIC5321-2.6/1.85YD6 MIC5321-KDYD6 MIC5321-2.6/1.8YD6 MIC5321-KGYD6 MIC5321-2.7/2.7YD6 MIC5321-LLYD6 QBLL MIC5321-2.8/1.5YD6 MIC5321-MFYD6 QBMF 2.8V/1.5V –40°C to +125°C 6-Pin TSOT-23 MIC5321-2.8/1.8YD6 MIC5321-MGYD6 QBMG 2.8V/1.8V –40°C to +125°C 6-Pin TSOT-23 MIC5321-2.8/2.6YD6 MIC5321-MKYD6 QBMK 2.8V/2.6V –40°C to +125°C 6-Pin TSOT-23 MIC5321-2.8/2.8YD6 MIC5321-MMYD6 QBMM 2.8V/2.8V –40°C to +125°C 6-Pin TSOT-23 MIC5321-2.8/2.85YD6 MIC5321-MNYD6 QBMN 2.8V/2.85V –40°C to +125°C 6-Pin TSOT-23 MIC5321-2.85/1.85YD6 MIC5321-NDYD6 QBND 2.85V/1.85V –40°C to +125°C 6-Pin TSOT-23 MIC5321-2.85/2.6YD6 MIC5321-NKYD6 QBNK 2.85V/2.6V –40°C to +125°C 6-Pin TSOT-23 MIC5321-2.85/2.85YD6 MIC5321-NNYD6 QBNN 2.85V/2.85V –40°C to +125°C 6-Pin TSOT-23 MIC5321-2.9/1.5YD6 MIC5321-OFYD6 QBOF 2.9V/1.5V –40°C to +125°C 6-Pin TSOT-23 MIC5321-2.9/1.8YD6 MIC5321-OGYD6 QBOG 2.9V/1.8V –40°C to +125°C 6-Pin TSOT-23 MIC5321-2.9/2.9YD6 MIC5321-OOYD6 QBOO 2.9V/2.9V –40°C to +125°C 6-Pin TSOT-23 MIC5321-3.0/1.8YD6 MIC5321-PGYD6 QBPG 3.0V/1.8V –40°C to +125°C 6-Pin TSOT-23 MIC5321-3.0/2.5YD6 MIC5321-PJYD6 QBPJ 3.0V/2.5V –40°C to +125°C 6-Pin TSOT-23 MIC5321-3.0/2.6YD6 MIC5321-PKYD6 QBPK 3.0V/2.6V –40°C to +125°C 6-Pin TSOT-23 MIC5321-3.0/2.8YD6 MIC5321-PMYD6 QBPM 3.0V/2.8V –40°C to +125°C 6-Pin TSOT-23 MIC5321-3.0/2.85YD6 MIC5321-PNYD6 QBPN 3.0V/2.85V –40°C to +125°C 6-Pin TSOT-23 MIC5321-3.0/3.0YD6 MIC5321-PPYD6 QBPP 3.0V/3.0V –40°C to +125°C 6-Pin TSOT-23 MIC5321-3.3/1.5YD6 MIC5321-SFYD6 QBSF 3.3V/1.5V –40°C to +125°C 6-Pin TSOT-23 MIC5321-3.3/1.8YD6 MIC5321-SGYD6 QBSG 3.3V/1.8V –40°C to +125°C 6-Pin TSOT-23 MIC5321-3.3/2.5YD6 MIC5321-SJYD6 QBSJ 3.3V/2.5V –40°C to +125°C 6-Pin TSOT-23 MIC5321-3.3/2.6YD6 MIC5321-SKYD6 QBSK 3.3V/2.6V –40°C to +125°C 6-Pin TSOT-23 MIC5321-3.3/2.7YD6 MIC5321-SLYD6 QBSL 3.3V/2.7V –40°C to +125°C 6-Pin TSOT-23 MIC5321-3.3/2.8YD6 MIC5321-SMYD6 QBSM 3.3V/2.8V –40°C to +125°C 6-Pin TSOT-23 MIC5321-3.3/2.85YD6 MIC5321-SNYD6 QBSN 3.3V/2.85V –40°C to +125°C 6-Pin TSOT-23 MIC5321-3.3/2.9YD6 MIC5321-SOYD6 QBSO 3.3V/2.9V –40°C to +125°C 6-Pin TSOT-23 Package 1.8V/1.5V Junction Temp. Range –40°C to +125°C 6-Pin TSOT-23 1.8V/1.6V –40°C to +125°C 6-Pin TSOT-23 QBJG 2.5V/1.8V –40°C to +125°C 6-Pin TSOT-23 QBJJ 2.5V/2.5V –40°C to +125°C 6-Pin TSOT-23 QBKD 2.6V/1.85 –40°C to +125°C 6-Pin TSOT-23 QBKG 2.6V/1.8V –40°C to +125°C 6-Pin TSOT-23 2.7V/2.7V –40°C to +125°C 6-Pin TSOT-23 MIC5321-3.3/3.0YD6 MIC5321-SPYD6 QBSP 3.3V/3.0V –40°C to +125°C 6-Pin TSOT-23 MIC5321-3.3/3.2YD6 MIC5321-SRYD6 QBSR 3.3V/3.2V –40°C to +125°C 6-Pin TSOT-23 MIC5321-3.3/3.3YD6 MIC5321-SSYD6 QBSS 3.3V/3.3V –40°C to +125°C 6-Pin TSOT-23 Note: * Under bar/Over bar symbol may not be to scale. ** For other voltages available. Contact Micrel Marketing for details. January 2007 3 M9999-012407-C 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 Thin MLF (MT) Top View EN TSOT-23-6 (D6) Top View Pin Description Pin Number Thin 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 0.01µF 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 January 2007 Enable Input (both regulators): Active High Input. Logic High = On; Logic Low = Off; Do not leave floating. 4 M9999-012407-C 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) ..................260°C Storage Temperature (TS) ................ –65°C to +150°C ESD Rating(4) .........................................................2kV Supply Voltage (VIN).............................. +2.3V to +5.5V Enable Input Voltage (VEN).............................. 0V to VIN Junction Temperature (TJ) ................. –40°C to +125°C Junction Thermal Resistance Thin MLF-6 (θJA) ..................................... 100°C/W TSOT-6 (θJA) ........................................... 235°C/W Electrical Characteristics(5) VIN = EN = VOUT + 1.0V; higher of the two regulator outputs, IOUTLDO1 = IOUTLDO2 = 100µA; COUT1 = COUT2 = 1µF; CBYP = 0.01µF; TJ = 25°C, bold values indicate –40°C ≤ TJ ≤ +125°C, unless noted. Parameter Conditions Output Voltage Accuracy Min Typ Max Units Variation from nominal VOUT -2.0 +2.0 % Variation from nominal VOUT; –40°C to +125°C -3.0 +3.0 % VIN = VOUT + 1V to 5.5V; IOUT = 100µA 0.02 0.3 0.6 %/V %/V IOUT = 100µA to 150mA 0.5 2.0 % IOUT = 100µA 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 µA Ground Current in Shutdown EN1 ≤ 0.2V 0.01 2 µA Ripple Rejection f = 1kHz; COUT = 1.0µF; CBYP = 0.1µF 75 dB f = 20kHz; COUT = 1.0µF; CBYP = 0.1µF 45 dB 300 Current Limit VOUT = 0V Output Voltage Noise COUT = 1.0µF; CBYP = 0.01µF; 10Hz to 100kHz 550 950 30 mA µVRMS 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 µA VIH ≥ 1.0V 0.01 1 µA COUT = 1.0µF; No CBYP 40 100 µs COUT = 1.0µF; CBYP = 0.01µF 45 100 µs 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) / 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, 1.5k 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 January 2007 5 M9999-012407-C Micrel, Inc. MIC5321 Functional Diagram VIN VOUT 1 LDO1 LDO2 VOUT 2 EN Enable BYP Reference GND MIC5321 Block Diagram January 2007 6 M9999-012407-C 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 = 1µF CBYP = 0.1µF 0 0.1 1 10 100 1,000 FREQUENCY (kHz) 20 Ground Current vs. Temperature 10 5 0 0 160 155 155 150 150 100µA 145 145 140 140 135 135 VIN = VOUT + 1V VOUT = 3V COUT = 1µF EN = VIN 130 125 20 40 60 80 TEMPERATURE (°C) Dropout Voltage vs. Temperature 50 VIN = VOUT + 1V 45 VOUT = 2.8V C 40 OUT = 1µF 35 30 25 20 15 10 5 0 162 120 2.90 25 50 75 100 125 150 OUTPUT CURRENT (mA) Ground Current vs. Temperature 100µA 20 40 60 80 TEMPERATURE (°C) Ground Current vs. Output Current 150 VIN = VOUT + 1V VOUT = 2.85V EN = VIN COUT1 = COUT2 = 1µF 142 25 50 75 100 125 150 OUTPUT CURRENT (mA) January 2007 2.55 2.50 3.0 2.5 150mA VIN = VOUT + 1V VOUT = 2.8V COUT = 1µF 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 = 1µF 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 = 100µA COUT = 1µF 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 = 1µF EN = VIN 2.70 0 25 50 75 100 125 150 OUTPUT CURRENT (mA) 1.45 VIN = VOUT + 1V VOUT = 1.5V COUT1 = COUT2 = 1µF EN = VIN 1.40 0 25 50 75 100 125 150 OUTPUT CURRENT (mA) 610 600 Current Limit vs. Input Voltage 10 590 580 570 560 154 146 2.70 2.65 2.60 100mA 158 138 0 125 VIN = VOUT + 1V VOUT = 2.8V COUT = 1µF EN = VIN 150mA 50mA 10mA 130 Output Voltage vs. Temperature 2.90 2.85 2.80 2.75 15 -30 120 3.00 2.95 25 -50 160 Dropout Voltage vs. Output Current 1 0.1 550 540 530 520 510 3 Output Noise Spectral Density EN = VIN COUT = 1µF 3.5 4 4.5 5 INPUT VOLTAGE (V) 7 5.5 0.01 VIN = 3.8V VOUT = 2.8V COUT = 1µF CBYP = 0.01µF 0.001 0.01 0.1 1 10 100 1,000 10,000 FREQUENCY (kHz) M9999-012407-C 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 = 1µF Output Current (50mA/div) CBYP = 0.1µF VOUT2 (1V/div) VIN = VOUT + 1V VOUT1 = VOUT2 = 3.0V COUT = 1µF CBYP = 0.1µF 10mA Time (10µs/div) Time (40µs/div) Line Transient 5.5V Input Voltage (2V/div) 4V VIN = VOUT + 1V VOUT = 2.8V COUT = 1µF Output Voltage (50mV/div) IOUT = 10mA Time (40µs/div) January 2007 8 M9999-012407-C 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 1µF 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 1µF 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 1µF 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 <150µA 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) × 150mA + (3.3V -1.5) × 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) = 125°C, the maximum junction temperature of the die θJA thermal resistance = 100°C/W. The table below shows junction-to-ambient thermal resistance for the MIC5321 in the Thin MLF® 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 0.1µF capacitor is recommended for applications that require low-noise outputs. The bypass capacitor can be January 2007 ⎛ ⎝ 9 M9999-012407-C Micrel, Inc. MIC5321 Package 6-Pin 1.6x1.6 Thin MLF ® θJA Recommended Minimum Footprint θJC 100°C/W 2°C/W For example, when operating the MIC5321-MFYMT 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: 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 100°C/W. The maximum power dissipation must not be exceeded for proper operation. 0.345W = (125°C – TA)/(100°C/W) TA=90.5°C Therefore, a 2.8V/1.5V application with 150mA at each output current can accept an ambient operating temperature of 90.5°C in a 1.6mm x 1.6mm Thin MLF® 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 January 2007 10 M9999-012407-C Micrel, Inc. MIC5321 Package Information 6-Pin 1.6mm x 1.6mm Thin MLF (MT) 6-Pin TSOT-23 (D6) January 2007 11 M9999-012407-C 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. © 2006 Micrel, Inc. January 2007 12 M9999-012407-C