MIC37501/37502 5A, Low Voltage μCap LDO Regulator General Description Features The MIC37501 and MIC37502 are 5A, low dropout linear voltage regulator that provide low voltage, high current outputs with a minimum of external components. They offer high precision, ultra-low dropout (500mV), and low ground current. The MIC37501and MIC37502 operate from an input of 2.3V to 6.0V. They are designed to drive digital circuits requiring low voltage at high currents (i.e., PLDs, DSPs, microcontrollers, etc.). They are 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. MIC37501 and MIC37502 LDOs feature thermal and currentlimit protection and reverse current protection. Logic enable and error flag pins are available. Junction temperature range of the MIC37501/02 is from –40°C to 125°C. For applications requiring input voltage greater than 6.0V, see MIC3910x, MIC3915x, MIC3930x, and MIC3950x LDOs. All 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: – MIC37501—7 terminal fixed voltage – MIC37502—5 (TO-263) and 7 (SPAK) 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 Applications VIN = 3.0V CIN MIC37501 VIN VOUT VIN VOUT VEN VOUT = 2.5V COUT 100F, Ceramic 100k FLG 450 400 DROPOUT (mV) GND Fixed 2.5V Regulator with Error Flag VIN CIN MIC37502 VIN VOUT VIN VOUT VEN 1.3V R1 ADJ GND Dropout vs. Output Current COUT 100F, Ceramic 350 300 250 2.5VOUT 200 150 100 50 0 R2 012345 OUTPUT CURRENT (A) Adjustable Regulator Super βeta is a registered trademark of Micrel 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 May 2011 1 M9999-050511-B Micrel, Inc. MIC37501/37502 Ordering Information Part Number RoHS Compliant(1) Standard Output Current Voltage(2) Junction Temp. Range Package –40°C to +125°C S-Pak-7 MIC37501-1.5BR MIC37501-1.5WR 5A 1.5V MIC37501-1.65BR MIC37501-1.65WR 5A 1.65V –40°C to +125°C S-Pak-7 MIC37501-1.8BR MIC37501-1.8WR 5A 1.8V –40°C to +125°C S-Pak-7 MIC37501-2.5BR MIC37501-2.5WR 5A 2.5V –40°C to +125°C S-Pak-7 MIC37501-3.3BR MIC37501-3.3WR 5A 3.3V –40°C to +125°C S-Pak-7 MIC37502BR MIC37502WR 5A Adj. –40°C to +125°C S-Pak-7 MIC37502BU MIC37502WU 5A Adj. –40°C to +125°C To-263-5 Notes: 1. RoHS compliant with “high-melting solder” exemption. 2. Other Voltage available. Contact Micrel for detail. Pin Configuration ADJ VOUT GND VIN EN 7 6 5 4 3 2 1 TAB TAB 5 4 3 2 1 TO-263-5 FLG/ADJ VOUT VOUT GND VIN VIN EN S-PAK-7 Pin Description Pin Number TO-263-5 Pin Number S-PAK-7 Pin Name 1 1 EN Enable (input): CMOS-compatible input. Logic high = enable, logic low = shutdown. 2 2, 3 VIN Input voltage which supplies current to the output power device. Connect pins 2 and 3 together externally. 3 4 GND Ground (TAB is connected to ground). 4 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. May 2011 Pin Name 2 M9999-050511-B Micrel, Inc. MIC37501/37502 Absolute Maximum Ratings(1) Operating Ratings(2) Supply Voltage (VIN) ................................................. 6.5V Enable Input Voltage (VEN) ....................................... 6.5V Power Dissipation(PD) .......................... Internally Limited Junction Temperature(TJ) ............... –40°C ≤ TJ ≤ +125°C Storage Temperature(TS) ............... –65°C ≤ TJ ≤ +150°C Lead Temperature (soldering, 5 sec.) ....................260°C ESD Rating(3) ...............................................................2kV Supply Voltage (VIN) ......................................... 2.3V to 6.0V Enable Input Voltage (VEN) .................................. 0V to 6.0V Junction Temperature Range(TJ) ....... –40°C ≤ TJ ≤ +125°C Maximum Power Dissipation .....................................Note 4 Package Thermal Resistance S-Pak(θJA) ......................................................... 38°C/W S-Pak(θJC) ........................................................... 2°C/W TO-263(θJA).................................................... 26.2°C/W TO-263(θJC)......................................................... 2°C/W Electrical Characteristics(5) TA = 25°C with VIN = VOUT + 1V; VEN = VIN; bold values indicate –40°C < TJ < +125°C; unless otherwise noted. Parameter Output Voltage Accuracy Condition Min 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 % (6) VIN – VOUT, Dropout Voltage Ground Pin Current (7) 350 mV IL = 5A 330 500 mV IL = 5A 57 100 mA IL = 2.5A Ground Pin Current in Shutdown VIL < 0.5V, VIN = VOUT + 1V Current Limit VOUT = 0 1.0 Start-up Time VEN = VIN, IOUT = 10mA, COUT = 100µF 5 µA 7.5 11 A 170 500 µs 0.8 V 2 4 µA µA 30 75 µA µA 1 2 µA µA 400 500 mV mV Enable Input Enable Input Threshold 2.25 Regulator enable V Regulator shutdown Enable Pin Input Current VIL < 0.8V (Regulator shutdown) VIH > 2.25V (Regulator enabled) 1 15 Flag Output IFLG(LEAK) VOH = 6V VFLG(LO) VIN = 2.25V, IOL = 250µA(8) VFLG 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 1.228 1.215 Reference Voltage Adjust Pin Bias Current May 2011 3 M9999-050511-B Micrel, Inc. MIC37501/37502 Notes: 1. Exceeding the ratings in the “Absolute Maximum Ratings” section may damage the device. 2. The device is not guaranteed to function outside its operating rating. 3. Devices are ESD sensitive. Handling precautions recommended. Human body model, 1.5kΩ in series with 100pF. 4. PD(max) = (TJ(max) – TA) / θJC, where θJC depends upon the printed circuit layout. See “Applications Information” section. 5. Specification for packaged product only 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 dut to a minimum input operating voltage of 2.3V. 7. IGND is the quiescent current. IIN = IGND + IOUT. 8. For a 2.5V device, VIN = 2.3V (device is in dropout). May 2011 4 M9999-050511-B Micrel, Inc. MIC37501/37502 Typical Characteristics 500 400 450 250 200 150 100 400 350 300 50 012345 OUTPUT CURRENT (A) 5A load 0.2 0 1.5 45 40 35 30 25 20 15 10 5 0 0.5 0.4 100mA 0.3 0.2 0.1 0 May 2011 10mA load 5A load 0.5 2.0 2.5 3.0 INPUT VOLTAGE (V) 0.2 10mA 0.5 0.4 100mA 0.3 0.2 0.1 90 60 50 2.5A 40 30 20 5A 10 012345 INPUT VOLTAGE (V) 5 10mA load 2.0 5A load 1.5 1.0 0.5 0 INPUT VOLTAGE (V) 80 Ground Current vs. Suppl (1.5V) 70 60 50 2.5A 40 30 20 5A 10 0 Ground Current vs. Suppl (1.8V) 70 2.5 2.5 3.5 012345 INPUT VOLTAGE (V) 80 1.7 1.9 2.1 2.3 INPUT VOLTAGE (V) Dropout Characteristics (3.3V) 3.0 Ground Current vs. Suppl (1.5V) 0.6 0 012345 INPUT VOLTAGE (V) 0.4 3.5 1.0 0 0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5 OUTPUT CURRENT (A) 10mA 0.6 1.5 5A load 0.6 0 1.5 Dropout Characteristics (2.5V) 2.0 0.7 Ground Current vs. Suppl (1.8V) 0.7 GROUND CURRENT (mA) Ground Current vs. Output Current 2.5VOUT 2.5 0 1.5 1.7 1.9 2.1 2.3 2.5 2.7 INPUT VOLTAGE (V) GROUND CURRENT (mA) GROUND CURRENT (mA) 50 OUTPUT VOLTAGE (V) 1.2 1 0.8 0.6 0.4 3.0 GROUND CURRENT (mA) OUTPUT VOLTAGE (V) Dropout Characteristics (1.8V) 2 10mA load 1.8 1.6 1.4 1 0.8 250 -40 -20 02 04 06 08 0 100 120 TEMPERATURE (°C) OUTPUT VOLTAGE (V) 0 1.2 1.5 1.8 2.0 2.3 2.5 2.8 3.0 3.3 3.5 3.8 4.0 4.3 2.5VOUT 10mA load 1.4 GROUND CURRENT (mA) 300 DROPOUT (mV) DROPOUT (mV) 350 Dropout Characteristics (1.5V) 1.6 2.5VOUT 1.8 GROUND CURRENT (mA) 450 Dropout vs. Temperature OUTPUT VOLTAGE (V) Dropout vs. Output Current 0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5 INPUT VOLTAGE (V) Ground Current vs. Suppl (2.5V) 1.6 1.4 1.2 1.0 0.8 0.6 0.4 100mA 10mA 0.2 0 012345 INPUT VOLTAGE (V) M9999-050511-B Micrel, Inc. MIC37501/37502 Ground Current vs. Supply (2.5V) Ground Current vs. Supply (3.3V) 0.08 0.06 5A 0.04 2.5A 0.02 0.5 0.4 0.80 100mA 0.60 10mA 0.40 0.20 0 5 01234 2.5A 40 20 0 5 01234 5 Ground Current vs. Temperature Ground Current vs. Temperature Output Voltage vs. Temperature 60 50 5A 40 30 20 2.5A 10 1A 0 -40 -20 02 04 06 08 0 100 120 TEMPERATURE (°C) 0 -40 -20 02 04 06 08 0 100 120 TEMPERATURE (°C) Short Circuit Current vs. Suppl Voltage Short Circuit Current vs. Temperature 5 4 3 2 1 3 3.75 4.5 5.25 SUPPLY VOLTAGE (V) 6 10 9 8 2.60 2.58 2.56 2.54 2.52 2.50 2.48 2.46 2.44 2.42 2.40 -40 -20 02 04 06 08 0 100 120 TEMPERATURE (°C) Error Flag Pull-Up Resistor 6 5 ERROR FLAG (V) 7 6 0 2.25 60 INPUT VOLTAGE (V) 0.3 0.2 0.1 10 9 8 80 INPUT VOLTAGE (V) 10m A 12 ENABLE CURRENT(μA) 1.00 5A 100 INPUT VOLTAGE (V) 100m A 0.7 0.6 1.20 OUTPUT VOLTAGE (V) 1 0.9 0.8 1.40 GROUND CURRENT (mA) GROUND CURRENT (mA) SHORT CIRCUIT CURRENT (A) 01234 1.60 GROUND CURRENT (mA) GROUND CURRENT (mA) 0.10 0 120 1.80 OUTPUT VOLTAGE (V) GROUND CURRENT (mA) 0.12 Ground Current vs. Supply (3.3V) 7 6 5 4 3 2 1 Flag High (OK) 4 3 2 Flag Low (FAULT) 1 0 -40 -20 02 04 06 08 0 100 120 TEMPERATURE (°C) VIN = 5V 0 0.01 0.1 1 10 100 ) 1k 10k Enable Current vs. Temperature 10 8 6 4 2 0 -40 -20 02 04 06 08 0 100 120 TEMPERATURE (°C) May 2011 6 M9999-050511-B Micrel, Inc. MIC37501/37502 Functional Characteristics Enable Transient Response Line Transient Response VIN = 3.3V VOUT = 2.5V COUT = 100µF Ceramic IOUT = 5A 5V 3.3V VIN = 3.3V VOUT = 2.5V COUT = 100µF Ceramic Load Transient Response Load Transient Response VIN = 3.3V VOUT = 2.5V COUT = 100µF Ceramic VIN = 3.3V VOUT = 2.5V COUT = 100µF Ceramic 5A 5A 1A 100mA May 2011 7 M9999-050511-B Micrel, Inc. MIC37501/37502 and the regulator. The low dropout properties of Micrel Super βeta 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. Refer to “Application Note 9” for further details and examples on thermal design and heat sink applications. Application Information The MIC37501/02 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 batterypowered systems and as a high-efficiency noise filter in post-regulator applications. Unlike older NPN-pass transistor designs, where 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 βeta PNP® process reduces this drive requirement to only 2% to 5% of the load current. The MIC37501/02 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. Output Capacitor The MIC37501/02 requires an output capacitor for stable operation. As a µCap LDO, the MIC37501/02 can operate with ceramic output capacitors as long as the amount of capacitance is 100µF or greater. For values of output capacitance lower than 100µF, the recommended ESR range is 200mΩ to 2Ω. The minimum value of output capacitance recommended for the MIC37501/02 is 47µF. For 100µF or greater, the ESR range recommended is less than 1Ω. Ultra-low ESR ceramic capacitors are recommended for output capacitance of 100µF 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. 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 data sheet. Input Capacitor An input capacitor of 1.0µF 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 placed 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. PD = (VIN – VOUT) IOUT + VIN IGND where the ground current is approximated by using numbers from the “Electrical Characteristics” or “Typical Characteristics” sections. The heat sink thermal resistance is then determined with this formula: θSA = ((TJ(max) – TA)/ PD) – (θJC + θCS) Transient Response and 3.3V to 2.5V, 2.5V to 1.8V or 1.65V, or 2.5V to 1.5V Conversions The MIC37501/02 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 47µF output capacitor is all Where TJ(max) ≤125°C and θCS is between 0°C and 2°C/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 May 2011 8 M9999-050511-B Micrel, Inc. MIC37501/37502 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 NPNbased designs. When converting from 3.3V to 2.5V, 2.5V to 1.8V or 1.65V, or 2.5V to 1.5V, the NPNbased 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 at least 3.7V. The MIC37501/02 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. Enable Input The MIC37501/02 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 up to VIN. When enabled, it draws approximately 15µA. Adjustable Regulator Design VIN ENABLE SHUTDOWN Minimum Load Current The MIC37501/02 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. R1 EN ADJ GND R2 VOUT COUT R1⎞ ⎛ VOUT = 1.240V ⎜1 + ⎟ ⎝ R2 ⎠ Figure 2. Adjustable Regulator with Resistors Error Flag The MIC37501 features an error flag circuit that monitors the output voltage and signals an error condition when the voltage drops 5% below the nominal output voltage. The error flag is an opencollector 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. May 2011 MIC37502 OUT IN 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 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 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 M9999-050511-B Micrel, Inc. MIC37501/37502 Package Information 7-Pin S-PAK (R) θ4 θ1 θ2 θ1 θ1 θ2 θ3 θ4 θ1 θ3 5-Pin TO-263 (U) May 2011 10 M9999-050511-B Micrel, Inc. MIC37501/37502 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 Micrel makes no representations or warranties with respect to the accuracy or completeness of the information furnished in this data sheet. This information is not intended as a warranty and Micrel does not assume responsibility for its use. Micrel reserves the right to change circuitry, specifications and descriptions at any time without notice. No license, whether express, implied, arising by estoppel or otherwise, to any intellectual property rights is granted by this document. Except as provided in Micrel’s terms and conditions of sale for such products, Micrel assumes no liability whatsoever, and Micrel disclaims any express or implied warranty relating to the sale and/or use of Micrel products including liability or warranties relating to fitness for a particular purpose, merchantability, or infringement of any patent, copyright or other intellectual property right. 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. © 2004 Micrel, Incorporated. May 2011 11 M9999-050511-B