MIC39300/39301/39302 3A, Low-Voltage Low-Dropout Regulator General Description Features The MIC39300, MIC39301 and MIC39302 are 3.0A lowdropout 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 MIC39300/1/2 offers extremely low dropout (typically 385mV at 3.0A) and low ground current (typically 36mA at 3.0A). The MIC39300/1/2 is ideal for PC add-in cards that need to convert from standard 3.3V to 2.5V or 2.5V to 1.8V. A guaranteed maximum dropout voltage of 500mV over all operating conditions allows the MIC39300/1/2 to provide 2.5V from a supply as low as 3V, and 1.8V from a supply as low as 2.5V. The MIC39300/1/2 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 MIC39300/1/2 is fully protected with overcurrent limiting, thermal shutdown, reversed-battery protection, reversed-leakage protection, and reversed-lead insertion. The MIC39301 offers a TTL-logic compatible enable pin and an error flag that indicates under voltage and over current conditions. Offered in fixed voltages, the MIC39300/1 comes in the TO-220 and TO-263 (D2Pak) packages and is an ideal upgrade to older, NPN-based linear voltage regulators. The MIC39302 adjustable option allows programming the output voltage anywhere between 1.24V and 15.5V and is offered in a 5-Pin, TO-263 (D2Pak) package. • • • • • • • • • • • • • • 3.0A minimum guaranteed output current 550mV maximum dropout voltage over temperature 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 protection Reversed-leakage protection Fast transient response TO-263 (D2Pak) and TO-220 packaging TTL/CMOS compatible enable pin (MIC39301/2 only) Error flag output (MIC39301 only) Adjustable output (MIC39302 only) Applications • • • • • • 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 _________________________________________________________________________________________________________________________ Typical Application MIC39300 MIC39301 MIC39302 Adjustable Output Application (*See Minimum Load Current Section) **See Thermal Load Current Section Super βeta PNP is a registered trademark of Micrel, Inc. 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 October 2009 M9999-102309-A Micrel, Inc. MIC39300/39301/39302 Ordering Information Part Number Standard Voltage Junction Temp Range Package 1.8V –40°C to +125°C 3-Pin TO-220 RoHS Compliant* MIC39300-1.8BT MIC39300-1.8WT MIC39300-1.8BU MIC39300-1.8WU 1.8V –40°C to +125°C 3-Pin TO-263 MIC39300-2.5BT MIC39300-2.5WT 2.5V –40°C to +125°C 3-Pin TO-220 MIC39300-2.5BU MIC39300-2.5WU 2.5V –40°C to +125°C 3-Pin TO-263 MIC39301-1.8BT MIC39301-1.8WT 1.8V –40°C to +125°C 5-Pin TO-220 MIC39301-1.8BU MIC39301-1.8WU 1.8V –40°C to +125°C 5-Pin TO-263 MIC39301-2.5BT MIC39301-2.5WT 2.5V –40°C to +125°C 5-Pin TO-220 MIC39301-2.5BU MIC39301-2.5WU 2.5V –40°C to +125°C 5-Pin TO-263 Adjustable –40°C to +125°C 5-Pin TO-263 — MIC39302WU Note: * RoHS compliant with ‘high-melting solder’ exemption. October 2009 2 M9999-102309-A Micrel, Inc. MIC39300/39301/39302 Pin Configuration MIC39300-x.xBT TO-220-3 (T) MIC39300-x.xBU TO-263-3 (U) MIC39301-x.xBT TO-220-5 (T) MIC39301-x.xBU 2 TO-263-5 (D Pak) (U) MIC39302WU TO-263-5 (D2Pak) (U) Pin Description Pin Number MIC39300 Pin Number MIC39301 Pin Number MIC39302 Pin Name — 1 1 EN Enable (Input): TTL/CMOS compatible input. Logic high = enable; logic low or open = shutdown. 1 2 2 IN Unregulated Input: +16V maximum supply. 2, TAB 3, TAB 3, TAB GND Ground: Ground pin and TAB are internally connected. 3 4 4 OUT Regulator Output — 5 — FLG Error Flag (Ouput): Open-collector indicates an output fault condition. Active low. — — 5 ADJ Adjustable Regulator Feedback Input: Connect to the resistor voltage divider that is placed from OUT to GND in order to set the output voltage. October 2009 Pin Function 3 M9999-102309-A Micrel, Inc. MIC39300/39301/39302 Absolute Maximum Ratings(1) Operating Ratings(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 Rating................................................................ Note 3 Supply Voltage (VIN)...................................... +2.5V 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(5) TJ = 25°C, bold values indicate –40°C ≤ TJ ≤ +125°C, unless noted. Symbol Parameter Condition VOUT Output Voltage 10mA 10mA ≤ IOUT ≤ 3A, VOUT + 1V ≤ VIN ≤ 8V Line Regulation IOUT = 10mA, VOUT + 1V ≤ VIN ≤ 8V Load Regulation VIN = VOUT + 1V, 10mA ≤ IOUT ≤ 3A ∆VOUT/∆T Min Typ Max Units 1 2 % % 0.06 0.5 % 0.2 1 % 20 100 ppm/°C 200 mV –1 –2 Output Voltage Temp. Coefficient Note 6 VDO IGND Dropout Voltage IOUT = 100mA, ∆VOUT = –1% 65 Note 7, Note 10 IOUT = 750mA, ∆VOUT = –1% 185 mV IOUT = 1.5A, ∆VOUT = –1% 250 mV IOUT = 3A, ∆VOUT = –1% 385 550 mV Ground Current IOUT = 750mA, VIN = VOUT + 1V 10 20 mA Note 8 IOUT = 1.5A, VIN = VOUT + 1V 17 mA IOUT = 3A, VIN = VOUT + 1V 45 mA 6 mA 4.5 A IGND(do) Dropout Ground Pin Current VIN ≤ VOUT(nominal) – 0.5V, IOUT = 10mA IOUT(lim) Current Limit VOUT = 0V, VIN = VOUT + 1V Enable Input (MIC39301) VEN Enable Input Voltage logic low (off) 0.8 logic high (on) IIN Enable Input Current V 2.5 VEN = 2.5V 15 30 75 µA µA 2 µA 4 µA 10 20 µA 1 2 µA µA 300 400 mV mV VEN = 0.8V IOUT(shdn) Shutdown Output Current Note 9 V Flag Output (MIC39301) IFLG(leak) Output Leakage Current VOH = 16V 0.01 VFLG(do) Output Low Voltage VIN = 2.50V, IOL, = 250µA, Note 10 220 VFLG Low Threshold % of VOUT High Threshold % of VOUT 93 99.2 Hysteresis October 2009 % 1 4 % % M9999-102309-A Micrel, Inc. Symbol MIC39300/39301/39302 Parameter Condition Min Typ Max Units 1.228 1.240 1.252 V 1.265 V Reference (Adjust Pin) – MIC39302 only VADJ Reference Voltage VTC Reference Voltage Temp. Coefficient IADJ 1.215 Note 11 20 40 Adjust Pin Bias Current ITC Adjust Pin Bias Current Temp. Coefficient 0.1 ppm/°C 80 nA 120 nA nA/°C Notes: 1. Exceeding the absolute maximum ratings may damage the device. 2. The device is not guaranteed to function outside its operating rating. 3. Devices are ESD sensitive. Handling precautions recommended. 4. PD(max) = (TJ(max) – TA) ÷ θJA, where θJA depends upon the printed circuit layout. See “Applications Information.” 5. Specification for packaged product only. 6. Output voltage temperature coefficient is ΔVOUT(worst case) ÷ (TJ(max) – TJ(min)) where TJ(max) is +125°C and TJ(min) is –40°C. 7. VDO = VIN – VOUT when VOUT decreases to 99% of its nominal output voltage with VIN = VOUT + 1V. For output voltages below 2.5V, dropout voltage is the input-to-output voltage differential with the minimum input voltage being 2.5V. Minimum input operating voltage is 2.5V. 8. IGND is the quiescent current. IIN = IGND + IOUT. 9. VEN ≤ 0.8V, VIN ≤ 8V, and VOUT = 0V 10. For a 1.8V device, VIN = 2.5V. 11. 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 = 8V for t = 10ms. October 2009 5 M9999-102309-A Micrel, Inc. MIC39300/39301/39302 Typical Characteristics October 2009 6 M9999-102309-A Micrel, Inc. MIC39300/39301/39302 Typical Characteristics (cont) October 2009 7 M9999-102309-A Micrel, Inc. MIC39300/39301/39302 Functional Characteristics October 2009 8 M9999-102309-A Micrel, Inc. MIC39300/39301/39302 Functional Diagram October 2009 9 M9999-102309-A Micrel, Inc. MIC39300/39301/39302 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 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 specification. Application Information The MIC39300/1/2 are high-performance, low-dropout voltage regulators suitable for moderate to high-current voltage regulator applications. Its 550mV 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 NPNpass 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 MIC39300/1/2 regulators are 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. Figure 1. Capacitor Requirements Output Capacitor The MIC39300/1/2 requires an output capacitor to maintain stability and improve transient response. Proper capacitor selection is important to ensure proper operation. The MIC39300/1/2 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. Ultralow ESR capacitors, such as ceramic chip capacitors may promote instability. These very low ESR levels may cause an oscillation and/or underdamped transient response. A low-ESR 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. Thermal Design Linear regulators are simple to use. The most complicated design parameters to consider are thermal characteristics. Thermal design requires four applicationspecific 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 the data sheet. 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, surface mount, ceramic chip capacitors can be used for the bypassing. 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 The heat sink thermal resistance is determined by: θSA = TJ(max) − TA PD − (θJC +θCS ) 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 compared with the dropout voltage. Use a series input resistor to drop excessive voltage and October 2009 10 M9999-102309-A Micrel, Inc. MIC39300/39301/39302 Enable Input The MIC39301/2 features an enable input for on/off control of the device. The enable input’s 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. When enabled, it draws approximately 15μA. Transient Response and 3.3V to 2.5V and 2.5V to 1.8V Conversions The MIC39300/1/2 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 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 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 MIC39300/1 regulator will provide excellent performance with an input as low as 3.0V or 2.5V. This gives the PNP-based regulators a distinct advantage over older, NPN-based linear regulators. Adjustable Regulator Design Figure 2. Adjustable Regulator with Resistors The MIC39302 allows programming the output voltage anywhere between 1.24V and 15.5V. Two resistors are used. The resistor values are calculated by: Minimum Load Current The MIC39300/1/2 regulators are 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. ⎞ ⎛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 Minimum Load Current section). Error Flag The MIC39301 version features an error flag circuit which monitors the output voltage and signals an error condition when the voltage drops 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. A pull-up resistor from FLG to either VIN or VOUT is required for proper operation. October 2009 11 M9999-102309-A Micrel, Inc. MIC39300/39301/39302 Package Information 3-Pin TO-220 (T) 5-Pin TO-220 (T) October 2009 12 M9999-102309-A Micrel, Inc. MIC39300/39301/39302 3-Pin TO-263 (U) 5-Pin TO-263 (U) 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 The 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. © 2009 Micrel, Incorporated. October 2009 13 M9999-102309-A