MIC5219 Micrel, Inc. MIC5219 500mA-Peak Output LDO Regulator General Description Features The MIC5219 is an efficient linear voltage regulator with high peak output current capability, very-low-dropout voltage, and better than 1% output voltage accuracy. Dropout is typically 10mV at light loads and less than 500mV at full load. * 500mA output current capability SOT-23-5 package - 500mA peak x2mm MLF package - 500mA continuous 2mmx MSOP-8 package - 500mA continuous * Low 500mV maximum dropout voltage at full load * Extremely tight load and line regulation * Tiny SOT-23-5 and MM8TM power MSOP-8 package * Ultra-low-noise output * Low temperature coefficient * Current and thermal limiting * Reversed-battery protection * CMOS/TTL-compatible enable/shutdown control * Near-zero shutdown current The MIC5219 is designed to provide a peak output current for start-up conditions where higher inrush current is demanded. It features a 500mA peak output rating. Continuous output current is limited only by package and layout. The MIC5219 can be enabled or shut down by a CMOS or TTL compatible signal. When disabled, power consumption drops nearly to zero. Dropout ground current is minimized to help prolong battery life. Other key features include reversedbattery protection, current limiting, overtemperature shutdown, and low noise performance with an ultra-low-noise option. Applications * * * * * * The MIC5219 is available in adjustable or fixed output voltages in the space-saving 6-pin (2mm x 2mm) MLFTM, SOT-23-5 and MM8TM 8-pin power MSOP packages. For higher power requirements see the MIC5209 or MIC5237. All support documentation can be found on Micrel's web site at www.micrel.com. Laptop, notebook, and palmtop computers Cellular telephones and battery-powered equipment Consumer and personal electronics PC Card VCC and VPP regulation and switching SMPS post-regulator/DC-to-DC modules High-efficiency linear power supplies Typical Applications MIC5219-5.0BMM ENABLE SHUTDOWN VIN 6V VOUT 5V 2.2F tantalum 1 8 2 7 3 6 4 5 MIC5219-3.3BM5 VIN 4V 1 5 2 ENABLE SHUTDOWN 3 4 VOUT 3.3V 2.2F tantalum 470pF 470pF 5V Ultra-Low-Noise Regulator 3.3V Ultra-Low-Noise Regulator VIN ENABLE SHUTDOWN VOUT MIC5219-x.xBML EN 1 6 2 5 3 4 CBYP (optional) COUT Ultra-Low-Noise Regulator MM8 is a trademark of Micrel, Inc. MicroLeadFrame and MLF are trademarks of Amkor Technology. Micrel, Inc. * 2180 Fortune Drive * San Jose, CA 95131 * USA * tel + 1 (408) 474-1000 * fax + 1 (408) 474-1000 * http://www.micrel.com March 2005 1 M999-031205 MIC5219 Micrel, Inc. Ordering Information Part Number Marking Standard Pb-Free Standard Pb-Free Volts Temp. Range Package MIC5219-2.5BMM MIC5219-2.5YMM -- -- 2.5V -40C to +125C MSOP-8 MIC5219-2.85BMM MIC5219-2.85YMM -- -- 2.85V -40C to +125C MSOP-8 MIC5219-3.0BMM MIC5219-3.0YMM -- -- 3.0V -40C to +125C MSOP-8 MIC5219-3.3BMM MIC5219-3.3YMM -- -- 3.3V -40C to +125C MSOP-8 MIC5219-3.6BMM MIC5219-3.6YMM -- -- 3.6V -40C to +125C MSOP-8 MIC5219-5.0BMM MIC5219-5.0YMM -- -- 5.0V -40C to +125C MSOP-8 -- MIC5219BMM MIC5219YMM -40C to +125C MSOP-8 MIC5219-2.5YM5 LG25 -- _ LG25* Adj. MIC5219-2.5BM5 2.5V -40C to +125C SOT-23-5 MIC5219-2.6BM5 MIC5219-2.6YM5 LG26 LG26 2.6V -40C to +125C SOT-23-5 MIC5219-2.7BM5 MIC5219-2.7YM5 LG27 LG27 2.7V -40C to +125C SOT-23-5 MIC5219-2.8BM5 MIC5219-2.8YM5 LG28 2.8V -40C to +125C SOT-23-5 MIC5219-2.8BML MIC5219-2.8YML G28 LG28 _ G28* 2.8V -40C to +125C 6-Pin 2x2 MLFTM MIC5219-2.85BM5 MIC5219-2.85YM5 LG2J LG2J 2.85V -40C to +125C SOT-23-5 MIC5219-2.9BM5 MIC5219-2.9YM5 LG29 LG29 2.9V -40C to +125C SOT-23-5 MIC5219-3.1BM5 MIC5219-3.1YM5 LG31 LG31 3.1V -40C to +125C SOT-23-5 MIC5219-3.0BM5 MIC5219-3.0YM5 LG30 -40C to +125C SOT-23-5 MIC5219-3.0YML G30 LG30 _ G30* 3.0V MIC5219-3.0BML 3.0V -40C to +125C 6-Pin 2x2 MLFTM MIC5219-3.3BM5 MIC5219-3.3YM5 LG33 MIC5219-3.3BML MIC5219-3.3YML MIC5219-3.6BM5 MIC5219-3.6YM5 MIC5219-5.0BM5 MIC5219-5.0YM5 MIC5219BM5 MIC5219YM5 3.3V -40C to +125C SOT-23-5 G33 LG33 _ G33* 3.3V -40C to +125C 6-Pin 2x2 MLFTM LG36 LG36 3.6V -40C to +125C SOT-23-5 LG50 LG50 5.0V -40C to +125C SOT-23-5 LGAA LGAA Adj. -40C to +125C SOT-23-5 Other voltages available. Consult Micrel for details. *Overbar symbol (_) may not be to scale. Physical symbol is after Pin 1 identifier. Pin Configuration EN GND IN EN 1 8 GND IN 2 7 GND OUT 3 6 GND GND 2 BYP 4 5 GND IN 3 MIC5219-x.xBMM MM8TM MSOP-8 Fixed Voltages (Top View) 6 BYP EN 1 4 OUT 8 GND IN 2 7 GND OUT 3 6 GND ADJ 4 5 GND 1 4 5 BYP OUT MIC5219-x.xBM5 SOT-23-5 Fixed Voltages (Top View) EN GND IN 3 2 1 Part Identification LGAA MIC5219YMM MIC5219BMM MM8TM MSOP-8 Adjustable Voltage (Top View) M999-031205 2 LGxx 5 NC MIC5219-x.xBML 6-Pin 2mm x 2mm MLFTM (ML) (Top View) EN 1 3 4 5 ADJ OUT MIC5219BM5 SOT-23-5 Adjustable Voltage (Top View) 2 March 2005 MIC5219 Micrel, Inc. Pin Description Pin No. MLFTM-6 Pin No. MSOP-8 Pin No. SOT-23-5 Pin Name Pin Function 3 2 1 IN Supply Input. 2 5-8 2 GND Ground: MSOP-8 pins 5 through 8 are internally connected. 4 3 5 OUT Regulator Output. 1 1 3 EN 6 4 (fixed) 4 (fixed) BYP Reference Bypass: Connect external 470pF capacitor to GND to reduce output noise. May be left open. 5(NC) 4 (adj.) 4 (adj.) ADJ Adjust (Input): Feedback input. Connect to resistive voltage-divider network. EP -- -- GND Ground: Internally connected to the exposed pad. Connect externally to GND pin. March 2005 Enable (Input): CMOS compatible control input. Logic high = enable; logic low or open = shutdown. 3 M999-031205 MIC5219 Micrel, Inc. Absolute Maximum Ratings(1) Operating Ratings(2) Supply Input Voltage (VIN) ............................ -20V to +20V Power Dissipation (PD) ............................ Internally Limited Junction Temperature (TJ) ....................... -40C to +125C Storage Temperature (TS) ....................... -65C to +150C Lead Temperature (Soldering, 5 sec.) ...................... 260C Supply Input Voltage (VIN) ........................... +2.5V to +12V Enable Input Voltage (VEN) .................................. 0V to VIN Junction Temperature (TJ) ....................... -40C to +125C Package Thermal Resistance ......................... see Table 1 Electrical Characteristics(3) VIN = VOUT + 1.0V; COUT = 4.7F, IOUT = 100A; TJ = 25C, bold values indicate -40C TJ +125C; unless noted. Symbol Parameter Conditions VOUT Output Voltage Accuracy variation from nominal VOUT VOUT/T Output Voltage Temperature Coefficient Note 4 VOUT/VOUT Line Regulation VIN = VOUT + 1V to 12V 0.009 0.05 0.1 %/V VOUT/VOUT Load Regulation IOUT = 100A to 500mA, Note 5 0.05 0.5 0.7 % VIN - VOUT Dropout Voltage(6) IOUT = 100A 10 60 80 mV IOUT = 50mA 115 175 250 mV IOUT = 150mA 175 300 400 mV IOUT = 500mA 350 500 600 mV VEN 3.0V, IOUT = 100A 80 130 170 A VEN 3.0V, IOUT = 50mA 350 650 900 A VEN 3.0V, IOUT = 150mA 1.8 2.5 3.0 mA VEN 3.0V, IOUT = 500mA 12 20 25 mA VEN 0.4V 0.05 3 A VEN 0.18V 0.10 8 A IGND Ground Pin Current(7, 8) Ground Pin Quiescent Current(8) Min Typical -1 -2 Max Units 1 2 % % 40 ppm/C PSRR Ripple Rejection f = 120Hz 75 ILIMIT Current Limit VOUT = 0V 700 VOUT/PD Thermal Regulation Note 9 0.05 %/W IOUT = 50mA, COUT = 2.2F, CBYP = 0 500 nV/ Hz IOUT = 50mA, COUT = 2.2F, CBYP = 470pF 300 nV/ Hz eno Output Noise(10) dB 1000 mA ENABLE Input VENL Enable Input Logic-Low Voltage VEN = logic low (regulator shutdown) VEN = logic high (regulator enabled) IENL IENH M999-031205 Enable Input Current 0.4 0.18 2.0 V V VENL 0.4V 0.01 -1 A VENL 0.18V 0.01 -2 A 5 20 25 A VENH 2.0V 2 4 March 2005 MIC5219 Micrel, Inc. Notes: 1. Absolute maximum ratings indicate limits beyond which damage to the component may occur. Electrical specifications do not apply when operating the device outside of its operating ratings. The maximum allowable power dissipation is a function of the maximum junction temperature, TJ(max), the junction-to-ambient thermal resistance, JA, and the ambient temperature, TA. The maximum allowable power dissipation at any ambient temperature is calculated using: PD(max) = (TJ(max) - AT) / JA. Exceeding the maximum allowable power dissipation will result in excessive die temperature, and the regulator will go into thermal shutdown. See Table 1 and the "Thermal Considerations" section for details. 2. The device is not guaranteed to function outside its operating rating. 3. Specification for packaged product only. 4. Output voltage temperature coefficient is defined as the worst case voltage change divided by the total temperature range. 5. Regulation is measured at constant junction temperature using low duty cycle pulse testing. Parts are tested for load regulation in the load range from 100A to 500mA. Changes in output voltage due to heating effects are covered by the thermal regulation specification. 6. 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. 7. Ground pin current is the regulator quiescent current plus pass transistor base current. The total current drawn from the supply is the sum of the load current plus the ground pin current. 8. VEN is the voltage externally applied to devices with the EN (enable) input pin. 9. Thermal regulation is defined as the change in output voltage at a time "t" after a change in power dissipation is applied, excluding load or line regulation effects. Specifications are for a 500mA load pulse at VIN = 12V for t = 10ms. 10. CBYP is an optional, external bypass capacitor connected to devices with a BYP (bypass) or ADJ (adjust) pin. March 2005 5 M999-031205 MIC5219 Micrel, Inc. Typical Characteristics Power Supply Rejection Ratio -40 -60 -80 -60 -80 0 PSRR (dB) -40 -60 IOUT = 100A COUT = 2.2F CBYP = 0.01F -100 1k 1E+4 10k 1E+5 1M 1E+7 1E+11E+2 10M 10 100 1E+3 100k 1E+6 FREQUENCY (Hz) Power Supply Ripple Rejection vs. Voltage Drop Power Supply Ripple Rejection vs. Voltage Drop 1mA 40 30 10mA IOUT = 100mA 20 10 COUT = 1F 0 10 0.1 0.2 0.3 VOLTAGE DROP (V) 0.4 Noise Performance 1 0.1 10mA 0.01 0.001 VOUT = 5V COUT = 10F electrolytic 1mA 0.0001 1E+11E+2 1k 1E+4 10 100 1E+3 1M 1E+7 10k 1E+5 100k 1E+6 10M FREQUENCY (Hz) M999-031205 1 IOUT = 100mA 10mA 30 20 COUT = 2.2F CBYP = 0.01F 0 0.1 0.2 0.3 VOLTAGE DROP (V) 0.1 0.01 0.001 0.4 VOUT = 5V 0.0001 1E+1 10 1E+2 1k 1E+4 100 1E+3 10k 1E+5 100k 1E+61E+7 1M 10M FREQUENCY (Hz) Dropout Voltage vs. Output Current Noise Performance 1 100mA Noise Performance 10mA, COUT = 1F 50 40 10 10 1mA 70 60 10 0 IOUT = 100mA COUT = 2.2F CBYP = 0.01F -100 1k 1E+4 10k 1E+5 1M 1E+7 1E+11E+2 10M 10 100 1E+3 100k 1E+6 FREQUENCY (Hz) NOISE (V/Hz) 90 80 RIPPLE REJECTION (dB) 50 -60 -80 -100 1k 1E+4 10k 1E+5 1M 1E+7 1E+11E+2 10M 10 100 1E+3 100k 1E+6 FREQUENCY (Hz) 100 -40 IOUT = 1mA COUT = 2.2F CBYP = 0.01F -80 60 VIN = 6V VOUT = 5V -20 100mA 0.1 0.01 1mA VOUT = 5V COUT = 10F 0.001 electrolytic 10mA CBYP = 100pF 0.0001 1E+11E+2 1k 1E+4 10 100 1E+3 1M 1E+7 10k 1E+5 100k 1E+6 10M FREQUENCY (Hz) 6 400 DROPOUT VOLTAGE (mV) PSRR (dB) -60 NOISE (V/Hz) PSRR (dB) Power Supply Rejection Ratio VIN = 6V VOUT = 5V -20 -40 RIPPLE REJECTION (dB) -100 1k 1E+4 10k 1E+5 1M 1E+7 1E+11E+2 10M 10 100 1E+3 100k 1E+6 FREQUENCY (Hz) 0 -80 IOUT = 100mA COUT = 1F Power Supply Rejection Ratio VIN = 6V VOUT = 5V -20 NOISE (V/Hz) -60 -80 -100 1k 1E+4 10k 1E+5 1M 1E+7 1E+11E+2 10M 10 100 1E+3 100k 1E+6 FREQUENCY (Hz) 0 0 -40 IOUT = 1mA COUT = 1F Power Supply Rejection Ratio VIN = 6V VOUT = 5V -20 -40 IOUT = 100A COUT = 1F -100 1k 1E+4 10k 1E+5 1M 1E+7 1E+11E+2 10M 10 100 1E+3 100k 1E+6 FREQUENCY (Hz) 0 VIN = 6V VOUT = 5V -20 PSRR (dB) -20 PSRR (dB) 0 VIN = 6V VOUT = 5V Power Supply Rejection Ratio PSRR (dB) 0 Power Supply Rejection Ratio 300 200 100 0 0 100 200 300 400 500 OUTPUT CURRENT (mA) March 2005 MIC5219 Micrel, Inc. Dropout Characteristics 2.5 2.0 1.5 IL=100mA 1.0 IL=500mA 0.5 0 0 1 2 3 4 5 6 7 8 INPUT VOLTAGE (V) 10 8 6 4 2 0 0 9 25 GROUND CURRENT (mA) 3.0 Ground Current vs. Supply Voltage 12 IL =100A GROUND CURRENT (mA) OUTPUT VOLTAGE (V) 3.5 Ground Current vs. Output Current 100 200 300 400 500 OUTPUT CURRENT (mA) 20 15 10 5 0 0 IL=500mA 1 2 3 4 5 6 7 8 INPUT VOLTAGE (V) 9 Ground Current vs. Supply Voltage GROUND CURRENT (mA) 3.0 2.5 2.0 1.5 0.5 0 0 March 2005 IL=100 mA 1.0 IL=100A 2 4 6 INPUT VOLTAGE (V) 7 8 M999-031205 MIC5219 Micrel, Inc. Block Diagrams VIN OUT IN VOUT COUT BYP CBYP (optional) Bandgap Ref. V REF EN Current Limit Thermal Shutdown MIC5219-x.xBM5/MM GND Ultra-Low-Noise Fixed Regulator VIN OUT IN VOUT R1 R2 Bandgap Ref. V REF COUT CBYP (optional) EN Current Limit Thermal Shutdown MIC5219BM5/MM [adj.] GND Ultra-Low-Noise Adjustable Regulator M999-031205 8 March 2005 MIC5219 Micrel, Inc. Applications Information Thermal Considerations The MIC5219 is designed for 150mA to 200mA output current applications where a high current spike (500mA) is needed for short, start-up conditions. Basic application of the device will be discussed initially followed by a more detailed discussion of higher current applications. The MIC5219 is designed to provide 200mA of continuous current in two very small profile packages. 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 thermal resistance, junction-to-ambient, of the device and the following basic equation. Enable/Shutdown Forcing EN (enable/shutdown) high (>2V) enables the regulator. EN is compatible with CMOS logic. If the enable/ shutdown feature is not required, connect EN to IN (supply input). See Figure 5. PD (max) = Input Capacitor J A 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 thermal resistance, junction-to-ambient, for the MIC5219. A 1F capacitor should be placed from IN to GND if there is more than 10 inches of wire between the input and the AC filter capacitor or if a battery is used as the input. Output Capacitor Package An output capacitor is required between OUT and GND to prevent oscillation. The minimum size of the output capacitor is dependent upon whether a reference bypass capacitor is used. 1F minimum is recommended when CBYP is not used (see Figure 5). 2.2F minimum is recommended when CBYP is 470pF (see Figure 6). For applications < 3V, the output capacitor should be increased to 22F minimum to reduce start-up overshoot. Larger values improve the regulator's transient response. The output capacitor value may be increased without limit. JA Recommended JA 1" Square Minimum Footprint 2oz. Copper JC MM8TM (MM) 160C/W 70C/W 30C/W SOT-23-5 (M5) 220C/W 170C/W 130C/W 2x2 MLFTM (ML) 90C/W -- -- Table 1. MIC5219 Thermal Resistance The actual power dissipation of the regulator circuit can be determined using one simple equation. PD = (VIN - VOUT) IOUT + VIN IGND The output capacitor should have an ESR (equivalent series resistance) of about 1 or less and a resonant frequency above 1MHz. Ultra-low-ESR capacitors could cause oscillation and/or underdamped transient response. Most tantalum or aluminum electrolytic capacitors are adequate; film types will work, but are more expensive. Many aluminum electrolytics have electrolytes that freeze at about -30C, so solid tantalums are recommended for operation below -25C. 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, if we are operating the MIC5219-3.3BM5 at room temperature, with a minimum footprint layout, we can determine the maximum input voltage for a set output current. PD (max) = At lower values of output current, less output capacitance is needed for stability. The capacitor can be reduced to 0.47F for current below 10mA, or 0.33F for currents below 1mA. (125C - 25C) 220C / W PD(max) = 455mW No-Load Stability The MIC5219 will remain stable and in regulation with no load (other than the internal voltage divider) unlike many other voltage regulators. This is especially important in CMOS RAM keep-alive applications. The thermal resistance, junction-to-ambient, for the minimum footprint is 220C/W, taken from Table 1. The maximum power dissipation number cannot be exceeded for proper operation of the device. Using the output voltage of 3.3V, and an output current of 150mA, we can determine the maximum input voltage. Ground current, maximum of 3mA for 150mA of output current, can be taken from the "Electrical Characteristics" section of the data sheet. Reference Bypass Capacitor BYP is connected to the internal voltage reference. A 470pF capacitor (CBYP) connected from BYP to GND quiets this reference, providing a significant reduction in output noise (ultra-low-noise performance). CBYP reduces the regulator phase margin; when using CBYP, output capacitors of 2.2F or greater are generally required to maintain stability. 455mW = (VIN - 3.3V) x 150mA + VIN x 3mA 455mW = (150mA) x VIN + 3mA x VIN - 495mW 950mW = 153mA x VIN VIN = 6.2VMAX Therefore, a 3.3V application at 150mA of output current can accept a maximum input voltage of 6.2V in a SOT-23-5 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. The start-up speed of the MIC5219 is inversely proportional to the size of the reference bypass capacitor. Applications requiring a slow ramp-up of output voltage should consider larger values of CBYP. Likewise, if rapid turn-on is necessary, consider omitting CBYP. March 2005 (T (max) - T ) 9 M999-031205 MIC5219 Micrel, Inc. resistance improves power dissipation and allows for a larger safe operating region. Peak Current Applications The MIC5219 is designed for applications where high startup currents are demanded from space constrained regulators. This device will deliver 500mA start-up current from a SOT-23-5 or MM8 package, allowing high power from a very low profile device. The MIC5219 can subsequently provide output current that is only limited by the thermal characteristics of the device. You can obtain higher continuous currents from the device with the proper design. This is easily proved with some thermal calculations. Figures 3 and 4 show safe operating regions for the MIC5219x.xBMM, the power MSOP package part. These graphs show three typical operating regions at different temperatures. The lower the temperature, the larger the operating region. The graphs were obtained in a similar way to the graphs for the MIC5219-x.xBM5, taking all factors into consideration and using two different board layouts, minimum footprint and 1" square copper PC board heat sink. (For further discussion of PC board heat sink characteristics, refer to "Application Hint 17, Designing PC Board Heat Sinks" .) If we look at a specific example, it may be easier to follow. The MIC5219 can be used to provide up to 500mA continuous output current. First, calculate the maximum power dissipation of the device, as was done in the thermal considerations section. Worst case thermal resistance (JA = 220C/W for the MIC5219-x.xBM5), will be used for this example. PD (max) = The information used to determine the safe operating regions can be obtained in a similar manner such as determining typical power dissipation, already discussed. Determining the maximum power dissipation based on the layout is the first step, this is done in the same manner as in the previous two sections. Then, a larger power dissipation number multiplied by a set maximum duty cycle would give that maximum power dissipation number for the layout. This is best shown through an example. If the application calls for 5V at 500mA for short pulses, but the only supply voltage available is 8V, then the duty cycle has to be adjusted to determine an average power that does not exceed the maximum power dissipation for the layout. (T (max) - T ) J A JA Assuming a 25C room temperature, we have a maximum power dissipation number of PD (max) = (125C - 25C) 220C / W PD(max) = 455mW % DC Avg.PD = V - VOUT IOUT + VIN IGND 100 IN ( Then we can determine the maximum input voltage for a 5volt regulator operating at 500mA, using worst case ground current. % DC 455mW = (8V - 5V) 500mA + 8V x 20mA 100 PD(max) = 455mW = (VIN - VOUT) IOUT + VIN IGND IOUT = 500mA % Duty Cycle 455mW = 1.66W 100 VOUT = 5V IGND = 20mA 455mW = (VIN - 5V) 500mA + VIN x 20mA 0.274 = 2.995W = 520mA x VIN % Duty Cycle 100 % Duty Cycle Max = 27.4% 2.955W VIN (max) = = 5.683V 520mA With an output current of 500mA and a three-volt drop across the MIC5219-xxBMM, the maximum duty cycle is 27.4%. Therefore, to be able to obtain a constant 500mA output current from the 5219-5.0BM5 at room temperature, you need extremely tight input-output voltage differential, barely above the maximum dropout voltage for that current rating. Applications also call for a set nominal current output with a greater amount of current needed for short durations. This is a tricky situation, but it is easily remedied. Calculate the average power dissipation for each current section, then add the two numbers giving the total power dissipation for the regulator. For example, if the regulator is operating normally at 50mA, but for 12.5% of the time it operates at 500mA output, the total power dissipation of the part can be easily determined. First, calculate the power dissipation of the device at 50mA. We will use the MIC5219-3.3BM5 with 5V input voltage as our example. You can run the part from larger supply voltages if the proper precautions are taken. Varying the duty cycle using the enable pin can increase the power dissipation of the device by maintaining a lower average power figure. This is ideal for applications where high current is only needed in short bursts. Figure 1 shows the safe operating regions for the MIC5219-x.xBM5 at three different ambient temperatures and at different output currents. The data used to determine this figure assumed a minimum footprint PCB design for minimum heat sinking. Figure 2 incorporates the same factors as the first figure, but assumes a much better heat sink. A 1" square copper trace on the PC board reduces the thermal resistance of the device. This improved thermal M999-031205 ) PD x 50mA = (5V - 3.3V) x 50mA + 5V x 650A PD x 50mA = 173mW 10 March 2005 MIC5219 Micrel, Inc. 10 10 10 6 200mA 4 300mA 400mA 2 8 100mA 6 200mA 4 300mA 2 400mA 500mA 0 0 20 40 60 80 DUTY CYCLE (%) 0 100 VOLTAGE DROP (V) 8 VOLTAGE DROP (V) VOLTAGE DROP (V) 100mA 0 a. 25C Ambient 20 500mA 40 60 80 DUTY CYCLE (%) 8 6 4 200mA 300mA 2 500mA 0 100 100mA 400mA 0 b. 50C Ambient 20 40 60 80 DUTY CYCLE (%) 100 c. 85C Ambient Figure 1. MIC5219-x.xBM5 (SOT-23-5) on Minimum Recommended Footprint 10 10 10 6 200mA 300mA 4 400mA 2 8 100mA 6 200mA 4 300mA 2 400mA 500mA 0 0 20 40 60 80 DUTY CYCLE (%) 0 100 VOLTAGE DROP (V) 8 VOLTAGE DROP (V) VOLTAGE DROP (V) 100mA 500mA 0 a. 25C Ambient 20 40 60 80 DUTY CYCLE (%) 8 100mA 6 200mA 4 2 0 100 300mA 400mA 500mA 20 40 60 80 DUTY CYCLE (%) 0 b. 50C Ambient 100 c. 85C Ambient Figure 2. MIC5219-x.xBM5 (SOT-23-5) on 1-inch2 Copper Cladding 10 10 10 100mA 200mA 6 300mA 4 400mA 2 8 6 200mA 300mA 4 400mA 2 500mA 0 0 20 VOLTAGE DROP (V) 8 VOLTAGE DROP (V) VOLTAGE DROP (V) 100mA 500mA 40 60 80 DUTY CYCLE (%) 0 100 0 a. 25C Ambient 20 40 60 80 DUTY CYCLE (%) 8 6 200mA 300mA 4 2 400mA 0 100 100mA 500mA 20 40 60 80 DUTY CYCLE (%) 0 b. 50C Ambient 100 c. 85C Ambient Figure 3. MIC5219-x.xBMM (MSOP-8) on Minimum Recommended Footprint 10 8 300mA 6 400mA 4 500mA 2 10 100mA 200mA 8 6 VOLTAGE DROP (V) 200mA VOLTAGE DROP (V) VOLTAGE DROP (V) 10 300mA 400mA 4 2 500mA 8 200mA 6 300mA 4 400mA 2 500mA 0 0 20 40 60 80 DUTY CYCLE (%) a. 25C Ambient 100 0 0 20 40 60 80 DUTY CYCLE (%) b. 50C Ambient 100 0 0 20 40 60 80 DUTY CYCLE (%) 100 c. 85C Ambient Figure 4. MIC5219-x.xBMM (MSOP-8) on 1-inch2 Copper Cladding March 2005 11 M999-031205 MIC5219 Micrel, Inc. However, this is continuous power dissipation, the actual on-time for the device at 50mA is (100%-12.5%) or 87.5% of the time, or 87.5% duty cycle. Therefore, PD must be multiplied by the duty cycle to obtain the actual average power dissipation at 50mA. Figure 5 shows a basic MIC5219-x.xBMX fixed-voltage regulator circuit. A 1F minimum output capacitor is required for basic fixed-voltage applications. MIC5219-x.x VIN IN PD x 50mA = 0.875 x 173mW EN PD x 50mA = 151mW VOUT OUT BYP GND 2.2F 470pF The power dissipation at 500mA must also be calculated. PD x 500mA = (5V - 3.3V) 500mA + 5V x 20mA PD x 500mA = 950mW Figure 6. Ultra-Low-Noise Fixed Voltage Regulator This number must be multiplied by the duty cycle at which it would be operating, 12.5%. Figure 6 includes the optional 470pF noise bypass capacitor between BYP and GND to reduce output noise. Note that the minimum value of COUT must be increased when the bypass capacitor is used. Adjustable Regulator Circuits PD x = 0.125 x 950mW PD x = 119mW The total power dissipation of the device under these conditions is the sum of the two power dissipation figures. MIC5219 VIN PD(total) = PD x 50mA + PD x 500mA IN PD(total) = 151mW + 119mW EN PD(total) = 270mW VOUT OUT ADJ GND R1 1F R2 The total power dissipation of the regulator is less than the maximum power dissipation of the SOT-23-5 package at room temperature, on a minimum footprint board and therefore would operate properly. Figure 7. Low-Noise Adjustable Voltage Regulator Multilayer boards with a ground plane, wide traces near the pads, and large supply-bus lines will have better thermal conductivity. Figure 7 shows the basic circuit for the MIC5219 adjustable regulator. The output voltage is configured by selecting values for R1 and R2 using the following formula: For additional heat sink characteristics, please refer to Micrel "Application Hint 17, Designing P.C. Board Heat Sinks", included in Micrel's Databook. For a full discussion of heat sinking and thermal effects on voltage regulators, refer to "Regulator Thermals" section of Micrel's Designing with LowDropout Voltage Regulators handbook. R2 VOUT = 1.242V + 1 R1 Although ADJ is a high-impedance input, for best performance, R2 should not exceed 470k. VIN Fixed Regulator Circuits VIN MIC5219-x.x IN EN IN EN VOUT OUT BYP GND MIC5219 VOUT OUT ADJ GND 470pF 1F R1 2.2F R2 Figure 8. Ultra-Low-Noise Adjustable Application Figure 5. Low-Noise Fixed Voltage Regulator M999-031205 Figure 8 includes the optional 470pF bypass capacitor from ADJ to GND to reduce output noise. 12 March 2005 MIC5219 Micrel, Inc. Package Information 0.199 (5.05) 0.187 (4.74) 0.122 (3.10) 0.112 (2.84) DIMENSIONS: INCH (MM) 0.120 (3.05) 0.116 (2.95) 0.036 (0.90) 0.032 (0.81) 0.043 (1.09) 0.038 (0.97) 0.007 (0.18) 0.005 (0.13) 0.012 (0.30) R 0.012 (0.03) 0.0256 (0.65) TYP 0.008 (0.20) 0.004 (0.10) 5 MAX 0 MIN 0.012 (0.03) R 0.039 (0.99) 0.035 (0.89) 0.021 (0.53) 8-Pin MSOP (MM) 1.90 (0.075) REF 0.95 (0.037) REF 1.75 (0.069) 1.50 (0.059) 3.00 (0.118) 2.60 (0.102) DIMENSIONS: MM (INCH) 3.02 (0.119) 2.80 (0.110) 0.50 (0.020) 0.35 (0.014) 1.30 (0.051) 0.90 (0.035) 0.20 (0.008) 0.09 (0.004) 10 0 0.15 (0.006) 0.00 (0.000) 0.60 (0.024) 0.10 (0.004) SOT-23-5 (M5) March 2005 13 M999-031205 MIC5219 Micrel, Inc. TOP VIEW BOTTOM VIEW Dimensions in millimeter SIDE VIEW Rev. 01 6-Pin MLFTM (ML) 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 This 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) 2003 Micrel, Incorporated. M999-031205 14 March 2005