MIC37150/37151/37152 Micrel MIC37150/37151/37152 1.5A, Low Voltage µCap LDO Regulator General Description Features The Micrel MIC37150/51/52 is a 1.5A low-dropout linear voltage regulator that provides a low voltage, high current output with a minimum of external components. It offers high precision, ultra-low dropout (500mV over temperature), and low ground current. The MIC37150/51/52 operates from an input of 2.25V to 6.0V. It is designed to drive digital circuits requiring low voltage at high currents (i.e., PLDs, DSPs, microcontrollers, etc.). It is available in fixed and adjustable output voltages. Fixed voltages include 1.5V, 1.65V, 1.8V, 2.5V and 3.3V. The adjustable version is capable of supplying output voltages from 1.24V to 5.5V. Features of the MIC37150/51/52 LDO include thermal and current limit protection, and reverse current and reverse battery protection. Logic enable and error flag pins are available. Junction temperature range of the MIC37150/51/52 is from –40°C to 125°C. For applications requiring input voltage greater than 6.0V, see MIC3910x, MIC3915x, MIC3930x, and MIC3950x LDOs. Data sheets and support documentation can be found on Micrel’s web site at www.micrel.com. • 1.5A minimum guaranteed output current • 500mV maximum dropout voltage over temperature Ideal for 3.0V to 2.5V conversion Ideal for 2.5V to 1.8V, 1.65V, or 1.5V conversion • Stable with ceramic or tantalum capacitor • Wide input voltage range: VIN: 2.25V to 6.0V • +1.0% initial output tolerance • Fixed and adjustable output voltages MIC37150—3-pin fixed voltages MIC37151—5-pin fixed voltages MIC37152—5-pin adjustable voltage • Excellent line and load regulation specifications • Logic controlled shutdown • Thermal shutdown and current limit protection • Reverse-leakage protection • Low profile S-Pak 3 or 5 pin packages Applications • • • • • LDO linear regulator for low-voltage digital IC PC add-in cards High efficiency linear power supplies SMPS post regulator Battery charger Typical Application VIN = 3.0V MIC37151 VIN VOUT CIN VOUT = 2.5V 100k VEN FLG COUT 47µF, Ceramic GND Fixed 2.5V Regulator with Error Flag VIN MIC37152 VIN VOUT 1.3V R1 CIN VEN COUT 47µF, Ceramic ADJ R2 GND Adjustable Regulator Super ßeta PNP is a trademark of Micrel, Inc. Micrel, Inc. • 1849 Fortune Drive • San Jose, CA 95131 • USA • tel + 1 (408) 944-0800 • fax + 1 (408) 944-0970 • http://www.micrel.com August 2003 1 MIC37150/37151/37152 MIC37150/37151/37152 Micrel Ordering Information Output Current Voltage* Junction Temp. Range Package MIC37150-1.5BR 1.5A 1.5V –40°C to +125°C S-Pak-3 MIC37150-1.65BR 1.5A 1.65V –40°C to +125°C S-Pak-3 MIC37150-1.8BR 1.5A 1.8V –40°C to +125°C S-Pak-3 MIC37150-2.5BR 1.5A 2.5V –40°C to +125°C S-Pak-3 MIC37150-3.3BR 1.5A 3.3V –40°C to +125°C S-Pak-3 MIC37151-1.5BR 1.5A 1.5V –40°C to +125°C S-Pak-5 MIC37151-1.65BR 1.5A 1.65V –40°C to +125°C S-Pak-5 MIC37151-1.8BR 1.5A 1.8V –40°C to +125°C S-Pak-5 MIC37151-2.5BR 1.5A 2.5V –40°C to +125°C S-Pak-5 MIC37151-3.3BR 1.5A 3.3V –40°C to +125°C S-Pak-5 MIC37152BR 1.5A ADJ. –40°C to +125°C S-Pak-5 Part Number *For other voltages contact Micrel. 3 OUT 2 GND 1 IN 5 4 3 2 1 TAB TAB Pin Configuration S-PAK-3 (R) MIC37150 FLG/ADJ VOUT GND VIN EN S-PAK-5 (R) MIC37151 MIC37152 Pin Description Pin Number MIC37150 S-PAK-3 Pin Number MIC37151/2 S-PAK-5 Pin Name – 1 EN Enable (Input): CMOS compatible input. Logic high = enable, logic low = shutdown. 1 2 VIN Input voltage which supplies current to the output power device. 2 3 GND Ground (TAB is connected to ground on S-Pak) 3 4 VOUT Regulator Output – 5 FLG MIC37151 only Error Flag (Output): Open collector output. Active low indicates an output fault condition. ADJ MIC37152 only Adjustable regulator feedback input. Connect to resistor voltage divider. MIC37150/37151/37152 Pin Function 2 August 2003 MIC37150/37151/37152 Micrel Absolute Maximum Rating (Note 1) Operating Maximum Rating (Note 2) Supply Voltage (VIN) .................................................... 6.5V Enable Input Voltage (VEN) .......................................... 6.5V Power Dissipation .................................... Internally Limited Junction Temperature ........................ –40°C ≤ TJ ≤ +125°C Storage Temperature ......................... –65°C ≤ TJ ≤ +150°C Lead Temperature (soldering, 5 sec.) ....................... 260°C ESD, Note 3 Supply Voltage (VIN) ..................................... 2.25V to 6.0V Enable Input Voltage (VEN) ................................ 0V to 6.0V Junction Temperature Range ............. –40°C ≤ TJ ≤ +125°C Maximum Power Dissipation .................................... Note 4 Package Thermal Resistance S-Pak(θJC) ......................................................... 2°C/W Electrical Characteristics (Note 5) TA = 25°C with VIN = VOUT + 1V; VEN = VIN; bold values indicate –40°C < TJ < +125°C; unless otherwise noted. Parameter Condition Min Output Voltage Accuracy IL = 10mA 10mA < IOUT < IL(max), VOUT + 1 ≤ VIN ≤ 6V Typ Max Units –1 +1 % –2 +2 % Output Voltage Line Regulation VIN = VOUT +1.0V to 6.0V 0.06 0.5 % Output Voltage Load Regulation IL = 10mA to 1.5A 0.2 1 % VIN – VOUT; Dropout Voltage; IL = 750mA 350 mV Note 6 IL = 1.5A 500 mV Ground Pin Current, Note 7 IL = 1.5A 17 30 mA Ground Pin Current in Shutdown VIL ≤ 0.5V, VIN = VOUT + 1V 1.0 Current Limit VOUT = 0 2.25 4.0 A Start-up Time VEN = VIN, IOUT = 10mA, COUT = 22µF 170 500 µs µA Enable Input Enable Input Threshold Regulator enable 2.25 V Regulator shutdown Enable Pin Input Current VIL ≤ 0.8V (regulator shutdown) VIH ≥ 2.25V (regulator enabled) 1 15 0.8 V 2 4 µA µA 30 µA 75 µA 1 µA 2 µA 300 mV 400 mV Flag Output IFLG(LEAK) VFLG(LO) VFLG VOH = 6V VIN = 2.25V, IOL = 250µA, Note 8 Low threshold, % of VOUT below nominal 210 93 Hysteresis % 2 High threshold, % of VOUT below nominal Reference Voltage Reference Voltage 1.228 Note 9 1.215 Adjust Pin Bias Current Reference Voltage Temp. Coefficient 40 Note 10 Adjust Pin Bias Current Temp. Coefficient August 2003 1.240 3 % 99.2 % 1.252 V 1.265 V 80 120 nA nA 20 ppm/°C 0.1 nA/°C MIC37150/37151/37152 MIC37150/37151/37152 Micrel Note 1. Exceeding the absolute maximum ratings may damage the device. Note 2. The device is not guaranteed to function outside its operating rating. Note 3. Device is ESD sensitive. Handling precautions recommended. Note 4. PD(MAX) = (TJ(MAX) – TA) / θJA, where θJA, depends upon the printed circuit layout. See “Applications Information.” Note 5. Specification for packaged product only. Note 6. VDO = VIN – VOUT when VOUT decreased to 98% of its nominal output voltage with VIN = VOUT +1V. For output voltages below 1.75V, dropout voltage specification does not apply due to a minimum input operating voltage of 2.25V. Note 7. Note 8. IGND is the quiescent current. IIN = IGND + IOUT. For a 2.5V device, VIN = 2.250V (device is in dropout). Note 9. VREF ≤ VOUT ≤ (VIN –1.0V), 2.25V ≤ VIN ≤ 6.0V, 10mA ≤ IL ≤ 1.5A, TJ = TMAX. Note 10. 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 200mA load pulse at VIN = 6V for t = 10ms. MIC37150/37151/37152 4 August 2003 MIC37150/37151/37152 Micrel Typical Characteristics Power Supply Rejection Ratio 80 60 0 0 18 1.5 1.5A 1.0 750mA 0.5 0 -40 -20 0 20 40 60 80 100 120 TEMPERATURE (°C) 14 12 10 1.5VOUT 8 6 4 2 0 0 1 1.5 2 2.5 3 INPUT VOLTAGE (V) 3.5 1600 100 50 100mA 1400 200 150 2.0 2.5VOUT 16 1200 250 2.5 0 2.5VOUT 400 800 1200 1600 OUTPUT CURRENT (mA) Ground Current vs. Output Current Dropout Characteristics 3.0 OUTPUT VOLTAGE (V) DROPOUT VOLTAGE (mV) 50 0 1E-2 1E+1 1 10 1E+2 1k 0.01 1E-1 100 1E+3 0.1 1E+0 FREQUENCY (Hz) Dropout Voltage vs. Temperature 450 400 350 300 100 800 0 1E-2 1E+1 1E+2 1 10 1k 0.01 1E-1 100 1E+3 0.1 1E+0 FREQUENCY (Hz) 500 IOUT = 1.5A COUT = 47µF CIN = 0 20 150 1000 IOUT = 1.5A COUT = 10µF CIN = 0 200 GROUND CURRENT (mA) 20 40 2.5VOUT 250 600 40 300 400 PSRR (dB) PSRR (dB) 60 350 VIN = 3.3V VOUT = 2.5V 200 VIN = 3.3V VOUT = 2.5V Dropout Voltage vs. Output Current DROPOUT VOLTAGE (mV) 80 Power Supply Rejection Ratio OUTPUT CURRENT (mA) Ground Current vs. Supply Voltage Ground Current vs. Supply Voltage GROUND CURRENT (mA) 1 0.8 100mA 0.6 0.4 0.2 0 0 10mA 1 2 3 4 5 SUPPLY VOLTAGE (V) 5.0 4 3 2 1 0 -40 -20 0 20 40 60 80 100 120 TEMPERATURE (°C) August 2003 GROUND CURRENT (mA) GROUND CURRENT (mA) 7 6 30 25 20 15 1500mA 10 1000mA 5 750mA 1 2 3 4 5 6 SUPPLY VOLTAGE (V) VOUT = 2.5V ILOAD = 10mA 0.44 0.435 0.43 0.4 0.42 0.415 0.41 0.405 0.4 -40 -20 0 20 40 60 80 100 120 TEMPERATURE (°C) Ground Current vs. Temperature Ground Current vs. Temperature VOUT = 2.5V ILOAD = 750mA 35 0 0 6 VOUT = 2.5V 40 20 18 VOUT =2.5V ILOAD = 1.5A 16 14 12 10 8 6 4 2 0 -40 -20 0 20 40 60 80 100 120 TEMPERATURE (°C) 5 SHORT CIRCUIT CURRENT (mA) GROUND CURRENT (mA) VOUT = 2.5V GROUND CURRENT (mA) 45 1.4 1.2 Ground Current vs. Temperature 0.5 0.445 3.0 Short Circuit Current vs. Temperature 2.5 2.0 1.5 1.0 0.5 0 -40 -20 0 20 40 60 80 100 120 TEMPERATURE (°C) MIC37150/37151/37152 MIC37150/37151/37152 6 Micrel Error Flag Pull-Up Resistor Output Voltage vs. Temperature Flag-Low Voltage vs. Temperature 2.60 2.58 250 FLAG HIGH (OK) 3 2 1 0 0.01 0.1 FLAG LOW (FAULT) 1 10 100 100010000 RESISTANCE (kΩ) MIC37150/37151/37152 200 150 100 50 V = 2.25V IN RPULL-UP = 22kΩ 0 -40 -20 0 20 40 60 80 100 120 TEMPERATURE (°C) 6 OUTPUT VOLTAGE (V) 4 FLAG VOLTAGE (mV) FLAG VOLTAGE (V) VIN = 5V 5 2.56 2.54 2.52 2.50 2.48 2.46 2.44 2.42 2.40 -40 -20 0 20 40 60 80 100 120 TEMPERATURE (°C) August 2003 MIC37150/37151/37152 Micrel Functional Characteristics Load Transient Response OUTPUT VOLTAGE (50mV/div.) OUTPUT VOLTAGE (50mV/div.) Load Transient Response VIN = 3.3V VOUT = 2.5V COUT = 47µF VIN = 3.3V VOUT = 2.5 COUT = 10µF 1.5A 3.3V 1.5A LOAD CURRENT (1A/div.) OUTPUT CURRENT (1A/div.) 5V 10mA 100mA TIME (400µs/div.) TIME (400µs/div.) VOUT = 2.5V COUT = 10µF 5V INPUT VOLTAGE (2V/div.) OUTPUT VOLTAGE (20mV/div.) Line Transient Response 3.3V TIME (250µs/div.) August 2003 7 MIC37150/37151/37152 MIC37150/37151/37152 Micrel Refer to “Application Note 9” for further details and examples on thermal design and heat sink applications. Output Capacitor The MIC37150/51/52 requires an output capacitor for stable operation. As a µCap LDO, the MIC37150/51/52 can operate with ceramic output capacitors as long as the amount of capacitance is 47µF or greater. For values of output capacitance lower than 47µF, the recommended ESR range is 200mΩ to 2Ω. The minimum value of output capacitance recommended for the MIC37151 is 10µF. For 47µF or greater, the ESR range recommended is less than 1Ω. Ultra-low ESR ceramic capacitors are recommended for output capacitance of 47µF or greater to help improve transient response and noise reduction at high frequency. X7R/X5R dielectric-type ceramic capacitors are recommended because of their temperature performance. X7Rtype 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. The MIC37150/51/52 has excellent transient response to variations in input voltage and load current. The device has been designed to respond quickly to load current variations and input voltage variations. Large output capacitors are not required to obtain this performance. A standard 47µF output capacitor, is all that is required. Larger values help to improve performance even further. Input Capacitor An input capacitor of 1.0µF or greater is recommended when the device is more than 4 inches away from the bulk and supply capacitance, or when the supply is a battery. Small, surface-mount chip capacitors can be used for the bypassing. The capacitor should be place within 1” of the device for optimal performance. Larger values will help to improve ripple rejection by bypassing the input to the regulator, further improving the integrity of the output voltage. Transient Response and 3.3V to 2.5V, 2.5V to 1.8V or 1.65V, or 2.5V to 1.5V Conversions The MIC37150/51/52 has excellent transient response to variations in input voltage and load current. The device has been designed to respond quickly to load current variations and input voltage variations. Large output capacitors are not required to obtain this performance. A standard 10µF output capacitor, preferably tantalum, is all that is required. Larger values help to improve performance even further. By virtue of its low dropout voltage, this device does not saturate into dropout as readily as similar NPN-based designs. When converting from 3.3V to 2.5V, 2.5V to 1.8V or 1.65V, or 2.5V to 1.5V, the NPN-based regulators are already operating in dropout, with typical dropout requirements of 1.2V or greater. To convert down to 2.5V without operating in dropout, NPN-based regulators require an input voltage of 3.7V at the very least. The MIC37150/51/52 regulator will provide excellent performance with an input as low as 3.0V or Applications Information The MIC37150/51/52 is a high-performance low-dropout voltage regulator suitable for moderate to high-current regulator applications. Its 500mV dropout voltage at full load and overtemperature makes it especially valuable in batterypowered systems and as high-efficiency noise filters in postregulator applications. Unlike older NPN-pass transistor designs, there the minimum dropout voltage is limited by the based-to-emitter voltage drop and collector-to-emitter saturation voltage, dropout performance of the PNP output of these devices is limited only by the low VCE saturation voltage. A trade-off for the low dropout voltage is a varying base drive requirement. Micrel’s Super ßeta PNP™ process reduces this drive requirement to only 2% to 5% of the load current. The MIC37150/51/52 regulator is fully protected from damage due to fault conditions. Current limiting is provided. This limiting is linear; output current during overload conditions is constant. Thermal shutdown disables the device when the die temperature exceeds the maximum safe operating temperature. Transient protection allows device (and load) survival even when the input voltage spikes above and below nominal. The output structure of these regulators allows voltages in excess of the desired output voltage to be applied without reverse current flow. Thermal Design Linear regulators are simple to use. The most complicated design parameters to consider are thermal characteristics. Thermal design requires the following application-specific parameters: • Maximum ambient temperature (TA) • Output current (IOUT) • Output voltage (VOUT) • Input voltage (VIN) • Ground current (IGND) First, calculate the power dissipation of the regulator from these numbers and the device parameters from this datasheet. PD = (VIN – VOUT) IOUT + VIN IGND where the ground current is approximated by using numbers from the “Electrical Characteristics” or “Typical Characteristics.” Then, the heat sink thermal resistance is determined with this formula: θSA = ((TJ(MAX) – TA)/ PD) – (θJC + θCS) Where TJ(MAX) ≤ 125oC and θCS is between 0oC and 2oC/W. The heat sink may be significantly reduced in applications where the minimum input voltage is known and is large compared with the dropout voltage. Use a series input resistor to drop excessive voltage and distribute the heat between this resistor and the regulator. The low dropout properties of Micrel Super ßeta PNP™ regulators allow significant reductions in regulator power dissipation and the associated heat sink without compromising performance. When this technique is employed, a capacitor of at least 1.0µF is needed directly between the input and regulator ground. MIC37150/37151/37152 8 August 2003 MIC37150/37151/37152 Micrel 2.25V, respectively. This gives the PNP-based regulators a distinct advantage over older, NPN-based linear regulators. Minimum Load Current The MIC37150/51/52 regulator is specified between finite loads. If the output current is too small, leakage currents dominate and the output voltage rises. A 10mA minimum load current is necessary for proper operation. Error Flag The MIC37151 features an error flag circuit that monitors the output voltage and signals an error condition when the voltage 5% below the nominal output voltage. The error flag is an open-collector output that can sink 10mA during a fault condition. Low output voltage can be caused by a number of problems, including an overcurrent fault (device in current limit) or low input voltage. The flag is inoperative during overtemperature shutdown. Enable Input The MIC37151/37152 also features an enable input for on/off control of the device. Its shutdown state draws “zero” current (only microamperes of leakage). The enable input is TTL/ CMOS compatible for simple logic interface, but can be connected to up to VIN. When enabled, it draws approximately 15µA. August 2003 Adjustable Regulator Design VIN MIC37152 OUT IN VOUT R1 ENABLE SHUTDOWN EN ADJ GND R2 COUT R1 VOUT = 1.240V 1 + R2 Figure 1. Adjustable Regulator with Resistors The MIC37152 allows programming the output voltage anywhere between 1.24V and the 5.5V maximum operating rating of the family. Two resistors are used. Resistors can be quite large, up to 1MΩ, because of the very high input impedance and low bias current of the sense comparator: The resistor values are calculated by: V R1 = R2 OUT − 1 1.240 Where VOUT is the desired output voltage. Figure 1 shows component definition. Applications with widely varying load currents may scale the resistors to draw the minimum load current required for proper operation (see above). 9 MIC37150/37151/37152 MIC37150/37151/37152 Micrel Package Information 0.050 (1.27) 0.030 (0.76) 0.375 (9.52) 0.365 (9.27) 0.360 (9.14) 0.350 (8.89) 0.256 BSC (6.50 BSC) 0.008 (0.20) 0.004 (0.10) 0.010 BSC (0.25 BSC) 0.316 BSC (8.03 BSC) 0.320 (8.13) 0.310 (7.87) 0.035 (0.89) 0.045 (1.14) 0.420 (0.20) 0.410 (0.10) 0.031 (0.79) 0.025 (0.63) 0.100 BSC (2.54 BSC) "A" DETAIL "A" 0.420 (0.20) 0.410 (0.10) 0.080 (2.03) 0.070 (1.78) 0.041 (1.04) 0.031 (0.79) 0.010 BSC (0.25 BSC) 0.041 (1.04) 0.031 (0.79) 6¡ 0¡ 3-Lead S-PAK (R) 0.370–0.005 9.395–0.125 0.040–0.010 1.015–0.255 0.315–0.005 8.000–0.130 0.355–0.005 9.015–0.125 0.075–0.005 1.905–0.125 0.256 6.50 0.010 0.250 0.040–0.005 1.015–0.125 0.316 BSC (8.03 BSC) 0.415–0.005 10.54–0.130 0.067 1.700 0.028–0.003 0.710–0.080 INCHES MILLIMETER 0.003–0.002 0.080–0.050 0.010 0.250 0.036–0.005 0.915–0.125 0¡ min 6¡ max 5-Lead S-PAK (R) MICREL, INC. 1849 FORTUNE DRIVE SAN JOSE, CA 95131 TEL + 1 (408) 944-0800 FAX + 1 (408) 944-0970 WEB USA http://www.micrel.com The information furnished by Micrel in this datasheet 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 at Purchaser’s own risk and Purchaser agrees to fully indemnify Micrel for any damages resulting from such use or sale. © 2003 Micrel, Incorporated. MIC37150/37151/37152 10 August 2003