MIC39500/39501 5A µCap Low-Voltage Low-Dropout Regulator General Description Features The MIC39500 and MIC39501 are 5A low-dropout linear voltage regulators that provide a low-voltage, high-current output with a minimum of external components. Utilizing Micrel’s proprietary Super βeta PNP™ pass element, the MIC39500/1 offers extremely low dropout (typically 400mV at 5A) and low ground current (typically 70mA at 5A). The MIC39500/1 is ideal for PC Add-In cards that need to convert from standard 2.5V or 3.3V, down to new, lower core voltages. A guaranteed maximum dropout voltage of 500mV over all operating conditions allows the MIC39500/1 to provide 2.5V from a supply as low as 3V or 1.8V from 2.5V. The MIC39500/1 also has fast transient response, for heavy switching applications. The device requires only 47µF of output capacitance to maintain stability and achieve fast transient response The MIC39500/1 is fully protected with overcurrent limiting, thermal shutdown, reversed-battery protection, reversedlead insertion protection, and reversed-leakage protection. The MIC39501 offers a TTL-logic-compatible enable pin and an error flag that indicates undervoltage and overcurrent conditions. Offered in a fixed voltages, 1.8V and 2.5V, the MIC39500/1 comes in the TO-220 and TO-263 packages and an ideal upgrade to older, NPN-based linear voltage regulators. • 5A minimum guaranteed output current • 400mV dropout voltage Ideal for 3.0V to 2.5V conversion Ideal for 2.5V to 1.8V conversion • 1% initial accuracy • Low ground current • Current limiting and thermal shutdown • Reversed-battery and reversed-lead insertion protection • Reversed-leakage protection • Fast transient response • TO-263 and TO-220 packages • TTL/CMOS compatible enable pin (MIC39501 only) • Error flag output (MIC39501 only) • Ceramic capacitor stable (See Application Information) Applications • • • • • • • Low Voltage Digital ICs LDO linear regulator for PC add-in cards High-efficiency linear power supplies SMPS post regulator Multimedia and PC processor supplies Low-voltage microcontrollers StrongARM™ processor supply For applications requiring input voltage greater than 16V, see the MIC29500/1/2/3 family. For applications with input voltage 6V or below, see MIC3750x LDOs. Typical Application 100KΩ MIC39501-2.5 VIN 3.3V 1.0µF MIC39500-2.5 IN VOUT 2.5V OUT GND 47µF Enable Shutdown EN VIN 3.3V IN 1.0µF MIC39500 FLG OUT GND ERROR FLAG OUTPUT VOUT 2.5V 47µF MIC39501 StrongARM is a trademark of Advanced RISC Machines, Ltd. Micrel, Inc. • 2180 Fortune Drive • San Jose, CA 95131 • USA • tel + 1 (408) 944-0800 • fax + 1 (408) 474-1000 • http://www.micrel.com August 2005 1 M9999-082605-B MIC39500/39501 Micrel Ordering Information Part Number Voltage Junction Temp. Range Package Standard RoHS Compliant* MIC39500-2.5BT MIC39500-2.5WT* 2.5V -40°C to +125°C 3-Lead TO-220 MIC39500-2.5BU MIC39500-2.5WU* 2.5V -40°C to +125°C 3-Lead TO-263 MIC39501-2.5BT MIC39501-2.5WT* 2.5V -40°C to +125°C 5-Lead TO-220 MIC39501-2.5BU MIC39501-2.5WU* 2.5V -40°C to +125°C 5-Lead TO-263 MIC39500-1.8BT MIC39500-1.8WT* 1.8V -40°C to +125°C 3-Lead TO-220 MIC39500-1.8BU MIC39500-1.8WU* 1.8V -40°C to +125°C 3-Lead TO-263 MIC39501-1.8BT MIC39501-1.8WT* 1.8V -40°C to +125°C 5-Lead TO-220 MIC39501-1.8BU MIC39501-1.8WU* 1.8V -40°C to +125°C 5-Lead TO-263 * RoHS compliant with high-melting solder exemption. 3 OUT 3 OUT 2 GND 2 GND 1 IN TAB TAB Pin Configuration 1 IN MIC39500-x.xBT TO-220-3 (T) MIC39500-x.xBU TO-263-3 (U) FLG OUT GND IN EN 5 4 3 2 1 TAB TAB 5 4 3 2 1 FLG OUT GND IN EN MIC39501-x.xBU TO-263-5 (U) MIC39501-x.xBT TO-220-5 (T) Pin Description Pin Number MIC39500 Pin Number MIC39501 Pin Name 1 EN Pin Function Enable (Input): TTL/CMOS compatible input. Logic high = enable; logic low or open = shutdown 1 2 IN 2, TAB 3, TAB GND 3 4 OUT Regulator Output 5 FLG Error Flag (Ouput): Open collector output. Active low indicates an output fault condition. M9999-082605-B Unregulated Input: +16V maximum supply. Ground: Ground pin and TAB are internally connected. 2 August 2005 MIC39500/39501 Micrel Absolute Maximum Ratings (Note 1) Operating Ratings (Note 2) Supply Voltage (VIN) .......................................–20V to +20V Enable Voltage (VEN) .................................................. +20V Storage Temperature (TS) ........................ –65°C to +150°C Lead Temperature (soldering, 5 sec.) ........................ 260°C ESD, Note 3 Supply Voltage (VIN) ................................... +2.25V to +16V Enable Voltage (VEN) .................................................. +16V Maximum Power Dissipation (PD(max)) ..................... Note 4 Junction Temperature (TJ) ........................ –40°C to +125°C Package Thermal Resistance TO-263 (θJC) ......................................................... 2°C/W TO-220 (θJC) ......................................................... 2°C/W Electrical Characteristics TJ = 25°C, bold values indicate –40°C ≤ TJ ≤ +125°C; unless noted Symbol Parameter Condition VOUT Output Voltage 10mA 10mA ≤ IOUT ≤ 5A, VOUT + 1V ≤ VIN ≤ 16V Line Regulation IOUT = 10mA, VOUT + 1V ≤ VIN ≤ 16V 0.06 Load Regulation VIN = VOUT + 1V, 10mA ≤ IOUT ≤ 5A ∆VOUT/∆T ppm/°C Output Voltage Temp. Coefficient, VDO Dropout Voltage, Note 6 Min Typ Max Units 1 2 % % 0.5 % 0.2 1 % 20 100 IOUT = 250mA, ∆VOUT = –2% 125 250 mV IOUT = 2.5A, ∆VOUT = –2% 320 IOUT = 5A, ∆VOUT = –2% 400 575 mV IOUT = 2.5A, VIN = VOUT + 1V 15 50 mA IOUT = 5A, VIN = VOUT + 1V 70 mA –1 1 –2 Note 5 Ground Current, Note 7 IGND mV IGND(do) Dropout Ground Pin Current VIN ≤ VOUT(nominal) – 0.5V, IOUT = 10mA 2.1 mA IOUT(lim) Current Limit VOUT = 0V, VIN = VOUT + 1V 7.5 A en µV(rms) Output Noise Voltage COUT = 47µF, IOUT = 100mA, 10Hz to 100kHz 260 Enable Input (MIC39501) VEN Enable Input Voltage IIN Enable Input Current 0.8 V 35 75 µA µA 2 4 µA µA 10 20 µA logic low (off) logic high (on) 2.25 VEN = VIN V 30 VEN = 0.8V IOUT(shdn) Shutdown Output Current Note 8 Flag Output (MIC39501) IFLG(leak) Output Leakage Current VOH = 16V 0.01 1 2 µA µA VFLG(do) Output Low Voltage VIN = 2.250V, IOL, = 250µA, Note 9 180 300 400 mV mV Low Threshold 1% of VOUT High Threshold 1% of VOUT VFLG 93 % 99.2 Hysteresis 1 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. Devices are 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. Output voltage temperature coefficient is ∆VOUT(worst case) ÷ (TJ(max) – TJ(min)) where TJ(max) is +125°C and TJ(min) is –40°C. Note 6. VDO = VIN – VOUT when VOUT decreases to 98% of its nominal output voltage with VIN = VOUT + 1V. For voltages below 2.25V, Dropout voltage is the input-to-output voltage differential with the minimum input voltage being 2.25V. Minimum input operating voltage is 2.25V. Note 7. IGND is the quiescent current. IIN = IGND + IOUT. Note 8. VEN ≤ 0.8V, VIN ≤ 8V, and VOUT = 0V Note 9. For a 2.5V device, VIN = 2.250V (device is in dropout). August 2005 3 M9999-082605-B MIC39500/39501 Micrel Typical Characteristics 10 5 C IN = 0 C OUT = 47µF T ant 0 1E+1 1E+2 1E+3 1E+4 1E+5 1E+6 10 100 1k 10k 100k 1M 10M FREQUENCY (Hz) 5 C IN = 0 C OUT = 100µF C eramic 0 1E+1 1E+2 1E+3 1E+4 1E+5 1E+6 10 100 1k 10k 100k 1M 10M FREQUENCY (Hz) 100 0 OUTPUT CURRENT (mA) I LOAD = 2.5A I LOAD = 5A 2.2 2 1.8 1.6 G round C urrent vs . S upply V oltage 180 0 1 2 3 4 5 6 7 8 9 10 SUPPLY VOLTAGE (V) 25 20 G round C urrent vs . T emperature 15 10 5 I LOAD = 2.5A V IN = V OUT + 1V 0 -40 -20 0 20 40 60 80 100 120 140 TEMPERATURE (°C) M9999-082605-B 100 80 I LOAD = 5.0A 60 I LOAD = 2.5A I LOAD = 2.0A 40 20 80.0 70.0 V OUT = 2.5V V OUT = 1.8V 120 0 0 GROUND CURRENT (mA) 30 140 GROUND CURRENT (mA) 2.0 30 20 V OUT = 1.8V 10 2 4 6 8 SUPPLY VOLTAGE (V) 10 G round C urrent vs . T emperature 50.0 V OUT = 1.8V 40.0 30.0 20.0 I LOAD = 5A V IN = V OUT = 1V 0 -40 -20 0 20 40 60 80 100 120 140 TEMPERATURE (°C) 4 9 8 7 6 5 4 3 V OUT = 2.5V V OUT = 1.8V 2 I LOAD = 10mA 1 V =V + 1V IN OUT 0 -40 -20 0 20 40 60 80 100 120 140 TEMPERATURE (°C) 10.0 V OUT = 2.5V 60.0 10.0 G round C urrent vs . Temperature 10 9.0 SHORT CIRCUIT CURRENT (A) I LOAD = 100mA 4.0 GROUND CURRENT (mA) 10.0 6.0 40 OUTPUT CURRENT (mA) 160 I LOAD = 10mA V OUT = 2.5V 50 1.4 1.6 1.8 2.0 2.2 2.4 2.6 2.8 3.0 3.2 3.4 3.6 G round C urrent vs . S upply V oltage 8.0 60 INPUT VOLTAGE (V) TEMPERATURE (°C) 12.0 V IN = V OUT +1V 0 1.4 140 120 80 100 60 40 0 20 -20 -40 I LOAD = 5A GROUND CURRENT (mA) 100 2.4 70 I LOAD = 100mA G round C urrent vs . Output C urrent 0 200 0 50 80 2.6 V OUT = 2.5V 300 V OUT = 2.5V 150 2.8 V OUT = 1.8V 400 GROUND CURRENT (mA) 200 Dropout C harac teris tic s Dropout V oltage vs . T emperature 500 0.0 250 4500 5000 10 300 2500 3000 3500 4000 15 350 3000 3500 4000 4500 5000 V IN = 3.3V V OUT = 2.5V 20 I LOAD = 5A 1500 2000 PSRR (dB) 15 V OUT = 1.8V 400 25 20 600 GROUND CURRENT (mA) 450 30 OUTPUT VOLTAGE (V) PSRR (dB) 25 Dropout V oltage vs . Output C urrent 0 500 1000 30 DROPOUT VOLTAGE (mV) 35 V IN = 3.3V V OUT = 2.5V I LOAD = 5A DROPOUT VOLTAGE (mV) 35 P ower S upply R ejection R atio 500 1000 1500 2000 2500 P ower S upply R ejection R atio S hort C irc uit C urrent vs . T emperature T ypical 2.5V Device 8.0 7.0 6.0 T ypical 1.8V Device 5.0 4.0 3.0 2.0 1.0 V IN = V OUT + 1V 0 -40 -20 0 20 40 60 80 100 120 140 TEMPERATURE (°C) August 2005 MIC39500/39501 6 Micrel E rror F lag P ull-up R es is tor 7 350 300 4 5 250 3 2 RESISTANCE (kΩ) August 2005 100000 1000 10000 10 100 1 0.001 0 F lag_LOW (F AULT ) 0.1 1 4 3 2 1 V E N = 2.25V V IN = V OUT + 1V 0 -40 -20 0 20 40 60 80 100 120 140 TEMPERATURE (°C) 5 FLAG VOLTAGE (V) 6 ENABLE CURRENT (µA) 5 0.01 FLAG VOLTAGE (V) F lag_HIG H (OK ) E nable C urrent vs . Temperature F lag L ow V oltage vs . Temperature 200 150 100 50 V IN = 2.8V R P ULL-UP = 22kΩ 0 -40 -20 0 20 40 60 80 100 120 140 TEMPERATURE (°C) M9999-082605-B MIC39500/39501 Micrel Functional Diagram IN OUT O.V. ILIMIT FLAG* 1.180V Ref. 18V 1.240V EN* Thermal Shutdown GND * MIC39501 only M9999-082605-B 6 August 2005 MIC39500/39501 Micrel Applications Information pared 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 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 1µF 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 specification. Output capacitor The MIC39500/1 requires an output capacitor to maintain stability and improve transient response. Proper capacitor selection is important to ensure proper operation. The MIC39500/1 output capacitor selection is dependent upon the ESR (equivalent series resistance) of the output capacitor to maintain stability. When the output capacitor is 47µF or greater, the output capacitor should have less than 1Ω of ESR. This will improve transient response as well as promote stability. Ultra-low-ESR capacitors, such as ceramic chip capacitors may promote instability. These very low ESR levels may cause an oscillation and/or underdamped transient response. When larger capacitors are used, the ESR requirement approaches zero. A 100µF ceramic capacitor can be used on the output while maintaining stability. A low-ESR 47µF solid tantalum capacitor works extremely well and provides good transient response and stability over temperature. Aluminum electrolytics can also be used, as long as the ESR of the capacitor is < 1Ω. The value of the output capacitor can be increased without limit. Higher capacitance values help to improve transient response and ripple rejection and reduce output noise. Input capacitor An input capacitor of 1µF or greater is recommended when the device is more than 4 inches away from the bulk ac supply capacitance, or when the supply is a battery. Small surfacemount ceramic chip capacitors can be used for bypassing. 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 or 2.5V to 1.8V Conversion The MIC39500/1 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, preferably tantalum, is all that is required. Larger values 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, or 2.5V to 1.8V, 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 MIC39500/1 regulator provides excellent performance The MIC39500/1 is a high-performance low-dropout voltage regulator suitable for moderate to high-current voltage regulator applications. Its 400mV dropout voltage at full load makes it especially valuable in battery-powered 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 base-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 MIC39500/1 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. VIN CIN MIC39500-x.x IN OUT GND VOUT COUT Figure 1. Capacitor Requirements Thermal Design Linear regulators are simple to use. The most complicated design parameters to consider are thermal characteristics. Thermal design requires four application-specific parameters: • Maximum ambient temperature (TA) • Output Current (IOUT) • Output Voltage (VOUT) • Input Voltage (VIN) • Ground Current (IGND) Calculate the power dissipation of the regulator from these numbers and the device parameters from this datasheet, where the ground current is taken from data sheet. PD = (VIN – VOUT) × IOUT + VIN × IGND The heat sink thermal resistance is determined by: where: TJ (max) ≤ 125°C and θCS is between 0° and 2°C/W. The heat sink may be significantly reduced in applications where the minimum input voltage is known and is large comAugust 2005 7 M9999-082605-B MIC39500/39501 Micrel Error Flag The MIC39501 version features an error flag circuit which 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. When the error flag is not used, it is best to leave it open. The flag pin can be tied directly to pin 4, the output pin. Enable Input The MIC39501 version 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 20V. with an input as low as 3.0V or 2.5V respectively. This gives PNP-based regulators a distinct advantage over older, NPNbased linear regulators. A typical NPN regulator does not have the headroom to do this conversion. Minimum Load Current The MIC39500/1 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 regulation. M9999-082605-B 8 August 2005 MIC39500/39501 Micrel Package Information 3-Lead TO-263 (U) 3-Lead TO-220 (T) August 2005 9 M9999-082605-B MIC39500/39501 Micrel θ4 θ1 θ2 θ1 θ1 θ3 5-Lead TO-263-5 (U) 5-Lead TO-220 (T) MICREL INC. TEL 2180 FORTUNE DRIVE SAN JOSE, CA 95131 USA + 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. © 2005 Micrel Incorporated M9999-082605-B 10 August 2005