MIC37500/37501/37502 Micrel MIC37500/37501/37502 5A, Low Voltage Cap LDO Regulator General Description Features The MIC37500/01/02 is a 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), and low ground current. The MIC37500/01/02 operates from an input of 2.3V 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 1.24V to 5.5V. Features of the MIC37500/01/02 LDO include thermal and current limit protection, and reverse current protection. Logic enable and error flag pins are available. Junction temperature range of the MIC37500/01/02 is from -40C to 125C. 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. * 5A minimum guaranteed output current * 500mV maximum dropout voltage 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: 2.3V to 6.0V * 1.0% initial output tolerance * Fixed and adjustable output voltages MIC37500--3 terminal fixed voltage MIC37501--5 terminal fixed voltage MIC37502--5 terminal adjustable voltage * Excellent line and load regulation specifications * Logic controlled shutdown * Thermal shutdown and current limit protection * Reverse-leakage protection * Low profile S-Pak and TO-263 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 CIN MIC37501 VIN VOUT VIN VOUT VEN VOUT = 2.5V 100k FLG COUT 100F, Ceramic Dropout vs. Output Current 450 GND DROPOUT (mV) 400 Fixed 2.5V Regulator with Error Flag VIN CIN MIC37502 VIN VOUT VIN VOUT VEN 1.3V GND 300 2.5VOUT 250 200 150 100 50 R1 COUT 100F, Ceramic ADJ 350 0 0 R2 1 2 3 4 OUTPUT CURRENT (A) 5 Adjustable Regulator Micrel, Inc. * 1849 Fortune Drive * San Jose, CA 95131 * USA * tel + 1 (408) 944-0800 * fax + 1 (408) 944-0970 * http://www.micrel.com July 2003 1 MIC37500/37501/37502 MIC37500/37501/37502 Micrel Ordering Information Output Current Voltage* Junction Temp. Range Package 5A 1.5V -40C to +125C S-Pak-5 MIC37500-1.65BR 5A 1.65V -40C to +125C S-Pak-5 MIC37500-1.8BR 5A 1.8V -40C to +125C S-Pak-5 MIC37500-2.5BR 5A 2.5V -40C to +125C S-Pak-5 MIC37500-3.3BR 5A 3.3V -40C to +125C S-Pak-5 MIC37501-1.5BR 5A 1.5V -40C to +125C S-Pak-7 MIC37501-1.65BR 5A 1.65V -40C to +125C S-Pak-7 MIC37501-1.8BR 5A 1.8V -40C to +125C S-Pak-7 MIC37501-2.5BR 5A 2.5V -40C to +125C S-Pak-7 MIC37501-3.3BR 5A 3.3V -40C to +125C S-Pak-7 MIC37502BR 5A ADJ. -40C to +125C S-Pak-7 MIC37502BU 5A ADJ -40C to +125C TO-263-5 Part Number MIC37500-1.5BR *For other voltages contact Micrel. Pin Configurations VOUT VOUT GND VIN VIN 7 6 5 4 3 2 1 TAB TAB 5 4 3 2 1 S-PAK-5 FLG/ADJ VOUT VOUT GND VIN VIN EN S-PAK-7 TAB 5 4 3 2 1 ADJ VOUT GND VIN EN TO-263-5 Pin Descriptions Pin Number Pin Number Pin Number TO-263-5 S-PAK-5 S-PAK-7 Pin Name Pin Function 1 -- 1 EN Enable (Input): CMOS compatible input. Logic high = enable, logic low = shutdown 2 1, 2 2, 3 VIN Input voltage which supplies current to the output power device. Connect pins 2 and 3 together externally. 3 3 4 GND Ground (TAB is connected to ground on S-Pak) 4 4, 5 5, 6 VOUT Regulator Output: Connect pins 5 and 6 together externally. -- -- 7 FLG Error Flag (Output): Open collector output. Active low indicates an output fault condition. 5 -- 7 ADJ Adjustable regulator feedback input. Connect to resistor voltage divider. MIC37500/37501/37502 2 July 2003 MIC37500/37501/37502 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 ........................ -40C TJ +125C Storage Temperature ........................ -65C TJ +150C Lead Temperature (soldering, 5 sec.) ....................... 260C ESD, Note 3 Supply Voltage (VIN) ....................................... 2.3V to 6.0V Enable Input Voltage (VEN) ................................ 0V to 6.0V Junction Temperature Range ............ -40C TJ +125C Maximum Power Dissipation .................................... Note 4 Package Thermal Resistance S-Pak(JC) ......................................................... 2C/W TO-263(JC) ...................................................... 2C/W Electrical Characteristics (Note 5) TA = 25C with VIN = VOUT + 1V; VEN = VIN; bold values indicate -40C < TJ < +125C; 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 5A 0.2 1 % VIN - VOUT, Dropout Voltage, IL = 2.5A 350 mV Note 6 IL = 5A 330 500 mV Ground Pin Current, Note 7 IL = 5A 57 100 mA Ground Pin Current in Shutdown VIL < 0.5V, VIN = VOUT + 1V 1.0 Current Limit VOUT = 0 Start-up Time VEN = VIN, IOUT = 10mA, COUT = 100F 5 A 7.5 10 A 170 500 s 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 A A 30 A 75 A 1 A 2 A 400 mV 500 mV Flag Output IFLG(LEAK) VFLG(LO) VFLG VOH = 6V VIN = 2.25V, IOL = 250A, Note 8 Low threshold, % of VOUT below nominal 210 93 Hysteresis % 2 High threshold, % of VOUT below nominal % 99.2 % 1.240 1.252 1.265 V V 40 80 120 nA nA MIC37502 Only Reference Voltage 1.228 1.215 Adjust Pin Bias Current July 2003 3 MIC37500/37501/37502 MIC37500/37501/37502 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) / JA, where JA, 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 2.3V. Note 7. IGND is the quiescent current. IIN = IGND + IOUT. Note 8. For a 2.5V device, VIN = 2.3V (device is in dropout). MIC37500/37501/37502 4 July 2003 MIC37500/37501/37502 Micrel Typical Characteristics Dropout vs. Output Current Dropout vs. Temperature 450 500 1.6 350 450 2.5VOUT 250 200 150 100 400 350 300 50 0 1 2 3 4 OUTPUT CURRENT (A) Dropout Characteristics (1.8V) 1 0.8 5A load 0.6 0.4 0.2 0 1.5 1.7 1.9 2.1 2.3 2.5 INPUT VOLTAGE (V) Ground Current vs. Output Current 40 35 30 25 20 15 10 5 2.0 5A load 1.5 1.0 0.5 100mA 0.2 0.1 0 1 2 3 4 INPUT VOLTAGE (V) 0.5 INPUT VOLTAGE (V) Ground Current vs. Supply (1.5V) 0.5 0.4 100mA 0.3 0.2 0.1 1 2 3 4 INPUT VOLTAGE (V) 70 60 50 30 20 5 Ground Current vs. Supply (2.5V) 1.8 80 1.6 70 60 2.5A 40 30 20 5A 10 90 50 2.5A 40 0 0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5 INPUT VOLTAGE (V) 5 GROUND CURRENT (mA) GROUND CURRENT (mA) GROUND CURRENT (mA) 0.4 0 1.0 Ground Current vs. Supply (1.8V) 0.5 0.3 5A load 1.5 80 Ground Current vs. Supply (1.8V) 10mA 2.5 10mA load 2.0 3.5 10mA 0 0.7 1.7 1.9 2.1 2.3 INPUT VOLTAGE (V) 2.5 Ground Current vs. Supply Voltage (1.5V) 0.6 0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5 OUTPUT CURRENT (A) 3.0 0 2.0 2.5 3.0 INPUT VOLTAGE (V) 0 0 0.6 0.2 Dropout Characteristics (3.3V) 10mA load 0.7 GROUND CURRENT (mA) GROUND CURRENT (mA) 2.5 0 1.5 2.7 2.5VOUT 0.4 3.5 OUTPUT VOLTAGE (V) OUTPUT VOLTAGE (V) OUTPUT VOLTAGE (V) 10mA load 5A load 0.6 0 1.5 3.0 1.4 1.2 0.8 Dropout Characteristics (2.5V) 2 1.8 1.6 1 250 -40 -20 0 20 40 60 80 100 120 TEMPERATURE (C) 5 10mA load 1.2 GROUND CURRENT (mA) 0 1.4 1.5 1.8 2.0 2.3 2.5 2.8 3.0 3.3 3.5 3.8 4.0 4.3 300 July 2003 OUTPUT VOLTAGE (V) 2.5VOUT DROPOUT (mV) DROPOUT (mV) 400 50 45 Dropout Characteristics (1.5V) 5A 10 0 1.4 1.2 1.0 0.8 100mA 0.6 0.4 10mA 0.2 0 0 1 2 3 4 INPUT VOLTAGE (V) 5 5 0 1 2 3 4 INPUT VOLTAGE (V) 5 MIC37500/37501/37502 MIC37500/37501/37502 Micrel Ground Current vs. Supply (2.5V) Ground Current vs. Supply (3.3V) 1.80 0.10 0.08 0.06 5A 0.04 2.5A 0.02 1 2 3 4 INPUT VOLTAGE (V) 1.40 1.20 1.00 0.80 0.40 10mA 0.20 0 0 5 1 2 3 4 INPUT VOLTAGE (V) 10mA 0.4 0.3 0.2 0.1 50 5A 40 30 20 2.5A 10 1A Short Circuit Current vs. Supply Voltage Short Circuit Current vs. Temperature 20 8 7 6 5 4 3 2 1 6 1 2 3 4 INPUT VOLTAGE (V) 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) Error Flag Pull-Up Resistor 10 9 6 8 7 5 ERROR FLAG (V) 10 9 2.5A Output Voltage vs. Temperature 0 -40 -20 0 20 40 60 80 100 120 TEMPERATURE (C) 3 3.75 4.5 5.25 SUPPLY VOLTAGE (V) 40 2.60 2.58 0 -40 -20 0 20 40 60 80 100 120 TEMPERATURE (C) 0 2.25 60 0 0 OUTPUT VOLTAGE (V) GROUND CURRENT (mA) 100mA 0.6 0.5 80 5 60 0.8 0.7 5A 100 Ground Current vs. Temperature 1 0.9 OUTPUT VOLTAGE (V) GROUND CURRENT (mA) 100mA 0.60 Ground Current vs. Temperature SHORT CIRCUIT CURRENT (A) 120 1.60 GROUND CURRENT (mA) GROUND CURRENT (mA) GROUND CURRENT (mA) 0.12 0 0 Ground Current vs. Supply (3.3V) 6 5 4 3 2 1 Flag High (OK) 4 3 2 1 0 -40 -20 0 20 40 60 80 100 120 TEMPERATURE (C) VIN = 5V 0 0.01 0.1 Flag Low (FAULT) 1 10 100 100010000 RESISTANCE (k) Enable Current vs. Temperature ENABLE CURRENT (A) 12 10 8 6 4 2 0 -40 -20 0 20 40 60 80 100 120 TEMPERATURE (C) MIC37500/37501/37502 6 July 2003 MIC37500/37501/37502 Micrel Functional Characteristics Line Transient Response OUTPUT VOLTAGE (20mV/div.) OUTPUT VOLTAGE (1V/div.) Enable Transient Response VIN = 3.3V VOUT = 2.5V COUT = 100F Ceramic IOUT = 5A 5V ENABLE (1V/div.) INPUT VOLTAGE (2V/div.) 3.3V TIME (20s/div.) TIME (100s/div.) Load Transient Response Load Transient Response VIN = 3.3V VOUT = 2.5V COUT = 100F Ceramic OUTPUT VOLTAGE (100mV/div.) OUTPUT VOLTAGE (100mV/div.) VIN = 3.3V VOUT = 2.5V COUT = 100F Ceramic VIN = 3.3V VOUT = 2.5V COUT = 100F Ceramic 5A July 2003 LOAD TRANSIENT (2A/div.) LOAD TRANSIENT (2A/div.) 5A 1A TIME (100s/div.) 7 100mA TIME (100s/div.) MIC37500/37501/37502 MIC37500/37501/37502 Micrel Output Capacitor The MIC37500/01/02 requires an output capacitor for stable operation. As a Cap LDO, the MIC37500/01/02 can operate with ceramic output capacitors as long as the amount of capacitance is 100F or greater. For values of output capacitance lower than 100F, the recommended ESR range is 200m to 2. The minimum value of output capacitance recommended for the MIC37500/01/02 is 47F. For 100F or greater the ESR range recommended is less than 1. Ultra-low ESR, ceramic capacitors are recommended for output capacitance of 100F 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. 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. Input Capacitor An input capacitor of 1.0F or greater is recommended when the device is more than 4 inches away from the bulk supply capacitance, or when the supply is a battery. Small, surfacemount 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 MIC37500/01/02 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 47F output capacitor, 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 MIC37500/01/02 regulator will provide excellent performance with an input as low as 3.0V or 2.25V, respectively. This gives the PNP-based regulators a distinct advantage over older, NPN-based linear regulators. Applications Information The MIC37500/01/02 is a high-performance low dropout voltage regulator suitable for moderate to high-current regulator applications. Its 500mV dropout voltage at full load makes it especially valuable in battery-powered systems and as high-efficiency noise filters in post-regulator 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 Beta PNPTM process reduces this drive requirement to only 2% to 5% of the load current. The MIC37500/01/02 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. 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: SA = ((TJ(MAX) - TA)/ PD) - (JC + CS) Where TJ(MAX) 125C and CS is between 0C and 2C/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 Beta 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 1.0F is needed directly between the input and regulator ground. Refer to "Application Note 9" for further details and examples on thermal design and heat sink applications. MIC37500/37501/37502 8 July 2003 MIC37500/37501/37502 Micrel Minimum Load Current The MIC37500/01/02 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 MIC37501 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 MIC37501/37502 also feature 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 15A. July 2003 Adjustable Regulator Design VIN MIC37502 OUT IN VOUT R1 ENABLE SHUTDOWN EN ADJ GND R2 COUT R1 VOUT = 1.240V 1 + R2 Figure 2. Adjustable Regulator with Resistors The MIC37502 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 1M, 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 2 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 MIC37500/37501/37502 MIC37500/37501/37502 Micrel Package Information 0.3700.005 9.3950.125 0.3550.005 9.0150.125 0.0400.010 1.0150.255 0.0750.005 1.9050.125 0.256 6.50 0.010 0.250 0.0400.005 1.0150.125 0.3150.005 8.0000.130 0.4150.005 10.540.130 0.067 1.700 INCHES MILLIMETER 0.0030.002 0.0800.050 0.010 0.250 0.0280.003 0.7100.080 0.0360.005 0.9150.125 0 min 6 max 5-Lead S-PAK (R) 0.375 (9.52) 0.365 (9.27) DIMENSIONS: INCH (MM) 0.360 (9.14) 0.350 (8.89) 0.050 (1.27) 0.030 (0.76) 0.320 (8.13) 0.310 (7.87) 0.050 BSC (1.27 BSC) 0.080 (2.03) 0.070 (1.78) 0.256 BSC (6.50 BSC) 0.010 BSC (0.25 BSC) 0.316 BSC (8.03 BSC) 0.420 (10.67) 0.410 (10.41) 0.045 (1.14) 0.035 (0.89) 0.031 (0.79) 0.025 (0.63) 0.005 (0.13) 0.001 (0.03) 0.010 BSC (0.25 BSC) 6 0 SCALE 20:1 7-Lead S-PAK (R) MIC37500/37501/37502 10 July 2003 MIC37500/37501/37502 Micrel 0.176 0.005 0.4050.005 0.065 0.010 202 0.060 0.005 0.0500.005 0.3600.005 0.6000.025 SEATING PLANE 0.004 +0.004 -0.008 0.100 0.01 8 MAX 0.032 0.003 0.0670.005 0.015 0.002 DIM. = INCH 5-Lead TO-263 (U) MICREL, INC. TEL 1849 FORTUNE DRIVE SAN JOSE, CA 95131 + 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. (c) 2003 Micrel, Incorporated. July 2003 11 MIC37500/37501/37502