MIC29510/29512 5A Fast-Response LDO Regulator General Description Features The MIC29510 and MIC29512 are high-current, highaccuracy, low-dropout voltage regulators featuring fast transient recovery from input voltage surges and output load current changes. These regulators use a PNP pass element that features Micrel’s proprietary Super ßeta PNP™ process. • Fast transient response The MIC29510/2 is available in two versions: the three pin fixed output MIC29510 and the five pin adjustable output voltage MIC29512. All versions are fully protected against overcurrent faults, reversed input polarity, reversed lead insertion, overtemperature operation, and positive and negative transient voltage spikes. • “Zero” current shutdown mode (MIC29512) A TTL compatible enable (EN) control pin supports external on/off control. If on/off control is not required, the device may be continuously enabled by connecting EN to IN. The MIC29510/2 is available in the standard three and five pin TO-220 package with an operating junction temperature range of 0°C to +125°C. • 5A current capability • 700mV dropout voltage at full load • Low ground current • Accurate 1% guaranteed tolerance • Fixed voltage and adjustable versions Applications • Pentium™, Pentium Plus™ and Power PC™ processor supplies • High-efficiency “green” computer systems • High-efficiency linear power supplies • High-efficiency switching supply post regulator • Battery-powered equipment For applications requiring even lower dropout voltage, input voltage greater than 16V, or an error flag, see the MIC29500/29501/29502/29503. Typical Application Fixed Regulator Configuration Adjustable Regulator Configuration Super ßeta PNP is a trademarks 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 2006 M9999-051706 (408) 955-1690 Micrel, Inc. MIC29510/29512 Ordering Information Part Number Junction Temp. Range Voltage Current Package MIC29510-3.3WT 0ºC to +125ºC 3.3V 5A TO-220-3 MIC29510-5.0WT 0ºC to +125ºC 5.0V 5A TO-220-3 MIC29512WT 0ºC to +125ºC Adj. 5A TO-220-5 Standard RoHS Compliant* MIC29510-3.3BT MIC29510-5.0BT MIC29512BT * RoHS compliant with ‘high-melting solder’ exemption. Pin Configuration 1 2 3 1234 5 MIC29510BT/WT MIC29512BT/WT On all devices, the Tab is grounded Pin Description 3-Pin TO-220 (MIC29510) Pin Number Pin Name 1 IN 2 GND Ground: Internally connected to tab (ground). 3 OUT Regulated Output. Pin Function Unregulated Input: +16V maximum supply. 5-Pin TO-220 (MIC29512) Pin Number Pin Name 1 EN Enable (Input): Logic-level ON/OFF control. 2 IN Unregulated Input: +16V maximum supply. 3 GND Ground: Internally connected to tab (ground). 4 OUT Regulated Output. 5 ADJ Output Voltage Adjust: 1.240V feedback from external resistive divider. May 2006 Pin Function 2 M9999-051706 (408) 955-1690 Micrel, Inc. MIC29510/29512 Absolute Maximum Ratings Operating Ratings (1) Input Supply Voltage ................................... –20V to +20V Power Dissipation .....................................Internally Limited Storage Temperature Range ....................–65°C to +150°C Ambient Temperature Range (soldering, 5 sec.) ....... 260°C Operating Junction Temperature ...................0ºC to +125ºC (θJC) (TO-220) ............................................................2°C/W (θJA) (TO-220)...........................................................55°C/W Electrical Characteristics All measurements at TJ = 25°C unless otherwise noted. Bold values are guaranteed across the operating temperature range. Parameter Conditions Min Typ Max ≤ I , (V + 1V) ≤ V ≤ 8V (Note 2) 10mA ≤ I O FL OUT IN –2 2 Output Voltage Units Line Regulation IO = 10mA, (VOUT + 1V) ≤ VIN ≤ 8V 0.06 0.5 % Load Regulation VIN = VOUT + 1V, 10mA ≤ IOUT ≤ IFULL LOAD (Notes 2, 6)) Output Voltage Temperature Coefficient (Note 6) 0.2 1 % 20 100 ppm/ºC 80 200 320 500 700 200 mV mV mV mV mV ∆VO/∆T Dropout Voltage ∆VOUT = – 1% (Note 3) MIC29510/29512 IO = 100mA IO = 750mA IO = 1.5A IO = 3A IO = 5A Ground Current MIC29510/29512 IO = 750mA, VIN = VOUT + 1V IO = 1.5A IO = 3A IO = 5A IGNDDO Ground Pin Current at Dropout VIN = 0.5V less than specified VOUT. IOUT = 10mA Current Limit MIC29510/29512 VOUT = 0V (Note 4) en, Output Noise Voltage (10Hz to 100kHz) IL = 100mA CL = 47µF 5.0 1000 % 3 10 36 100 150 mA mA mA mA 2 3 mA 20 6.5 A 260 µVRMS Reference (MIC29512 only) Parameter Reference Voltage Conditions 10mA ≤ IO ≤ IFL, VOUT + 1V ≤ VIN ≤ 8V (Note 2) Adjust Pin Bias Current Reference Voltage Temperature Coefficient Typ 1.215 40 (Note 7) Adjust Pin Bias Current Temperature Coefficient May 2006 Min 3 Max Units 1.265 VMAX 80 120 nA nA 20 ppm/ºC 0.1 nA/ºC M9999-051706 (408) 955-1690 Micrel, Inc. MIC29510/29512 Enable Input (MIC29512 only) Parameter Conditions Min Input Logic Voltage Low (Off) High (On) 2.4 Enable (EN) Pin Input Current Regulator Output Current in Shutdown Typ Max Units 0.8 V V VEN = VIN 15 30 75 µA µA VEN = 0.8V – 2 4 µA µA (Note 8) 10 20 µA µA Notes: General Note: Devices are ESD sensitive. Handling precautions are recommended. 1. The maximum continuous supply voltage is 16V. 2. Full Load current is defined as 5A for the MIC29510/29512. For testing, VOUT is programmed to 5V. 3. Dropout voltage defined as the input-to-output differential when the output voltage drops to 99% of its nominal value with VOUT + 1V applied to VIN. 4. For this test, VIN is the larger of 8V or VOUT + 3V. 5. Ground pin current is regulator quiescent current. Total current drawn from the source is the sum of the load current plus the ground pin current. 6. Output voltage temperature coefficient is defined as the worst case voltage change divided by the total temperature range. 7. VREF ≤ VOUT ≤ (VIN – 1V), 2.4V ≤ VIN ≤ 16V, 10mA < IL ≤ IFL, TJ ≤ TJ MAX. 8. VEN ≤ 0.8V and VIN ≤ 8V, VOUT = 0. Block Diagram 16V May 2006 4 M9999-051706 (408) 955-1690 Micrel, Inc. MIC29510/29512 Typical Characteristics MIC29512 Load Transient Response Test Circuit May 2006 5 M9999-051706 (408) 955-1690 Micrel, Inc. MIC29510/29512 GROUND CURRENT (mA) 2.5 MIC2951x Ground Current vs. Input Voltage 2.0 VOUT = 3.3V 1.5 1.0 0.5 0.0 -0.5 -20 RLOAD = 100 -10 0 10 INPUT VOLTAGE (V) 20 OUTPUT VOLTAGE (V) MIC29510-3.3 Output Voltage vs. Temperature MIC29512 Enable Current vs. Temperaure 40 30 VEN = 5V 20 10 VEN = 2V 0 -60 -30 0 30 60 90 120 150 TEMPERATURE °C) ( May 2006 MIC29512 Adjust Pin Current vs. Temperature 80 ADJUST PIN CURRENT (nA) ENABLE CURRENT (µA) 50 3.40 3.38 3.36 3.34 3.32 3.30 3.28 3.26 3 DEVICES 3.24 3.22 3.20 -60 -30 0 30 60 90 120 150 TEMPERATURE °C) ( 60 40 20 ILOAD = 10mA 0 -60 -30 0 30 60 90 120 150 TEMPERATURE °C) ( 6 M9999-051706 (408) 955-1690 Micrel, Inc. MIC29510/29512 Applications Information 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: The MIC29510 and MIC29512 are high performance low-dropout voltage regulators suitable for all moderate to high-current voltage regulator applications. Their 600mV of dropout voltage at full load make them especially valuable in battery powered systems and as high efficiency noise filters in “post-regulator” applications. Unlike older NPN-pass transistor designs, where the minimum dropout voltage is limited by the base-emitter voltage drop and collector-emitter saturation voltage, dropout performance of the PNP output of these devices is limited merely by the low VCE saturation voltage. • Maximum ambient temperature, TA • Output Current, IOUT • Output Voltage, VOUT • Input Voltage, VIN First, we calculate the power dissipation of the regulator from these numbers and the device parameters from this datasheet. A trade-off for the low dropout voltage is a varying base drive requirement. But Micrel’s Super ßeta PNP™ process reduces this drive requirement to merely 2 to 5% of the load current. PD = IOUT × (1.02VIN – VOUT) Where the ground current is approximated by 3% of IOUT, then the heat sink thermal resistance is determined with this formula: MIC29510/512 regulators are fully protected from damage due to fault conditions. Current limiting is provided. This limiting is linear; output current under overload conditions is constant. Thermal shutdown disables the device when the die temperature exceeds the maximum safe operating temperature. θ SA = TJ(MAX) − TA PD − (θ JC + θ CS ) 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 distribute the heat between this resistor and the regulator. The low dropout properties of Micrel Super ßeta PNP regulators allow very significant reductions in regulator power dissipation and the associated heat sink without compromising performance. When this technique is employed, a capacitor of at least 0.1µF is needed directly between the input and regulator ground. Transient protection allows device (and load) survival even when the input voltage spike 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. The MIC29512 version offers a logic level ON/OFF control: when disabled, the devices draw nearly zero current. An additional feature of this regulator family is a common pinout: a design’s current requirement may change up or down yet use the same board layout, as all of Micrel’s high-current Super ßeta PNP™ regulators have identical pinouts. Please refer to Application Note 9 for further details and examples on thermal design and heat sink specification. Capacitor Requirements For stability and minimum output noise, a capacitor on the regulator output is necessary. The value of this capacitor is dependent upon the output current; lower currents allow smaller capacitors. MIC29510/2 regulators are stable with a minimum capacitor value of 47µF at full load. This capacitor need not be an expensive low ESR type: aluminum electrolytics are adequate. In fact, extremely low ESR capacitors may contribute to instability. Tantalum capacitors are recommended for systems where fast load transient response is important. Figure 3. The MIC29510 requires only two capacitors for operation May 2006 7 M9999-051706 (408) 955-1690 Micrel, Inc. MIC29510/29512 Where the regulator is powered from a source with high AC impedance, a 0.1µF capacitor connected between Input and GND is recommended. This capacitor should have good characteristics to above 250kHz. Where VO is the desired output voltage. Figure 4 shows component definition. Adjustable Regulator Design Transient Response and 5V to 3.3V Conversion The MIC29510/2 have excellent response to variations in input voltage and load current. By virtue of their low dropout voltage, these devices do not saturate into dropout as readily as similar NPN-based designs. A 3.3V output Micrel LDO will maintain full speed and performance with an input supply as low as 4.2V, and will still provide some regulation with supplies down to 3.8V, unlike NPN devices that require 5.1V or more for good performance and become nothing more than a resistor under 4.6V of input. Micrel’s PNP regulators provide superior performance in “5V to 3.3V” conversion applications, especially when all tolerances are considered. Adjustable Regulator Design The adjustable regulator version, MIC29512, allows programming the output voltage anywhere between 1.25V and the 16V maximum operating rating of the family. Two resistors are used. Resistors can be quite large, up to 100kΩ, because of the very high input impedance and low bias current of the sense comparator. The resistor values are calculated by: Figure 4. Adjustable Regulator with Resistors Enable Input The MIC29512 version features an enable (EN) input that allows ON/OFF control of the device. Special design allows “zero” current drain when the device is disabled— only microamperes of leakage current flows. The EN input has TTL/CMOS compatible thresholds for simple interfacing with logic, or may be directly tied to VIN. Enabling the regulator requires approximately 20µA of current into the EN pin. ⎞ ⎛V R1 = R2 × ⎜⎜ OUT − 1⎟⎟ ⎠ ⎝ 1.240 Voltage Standard (Ω) R1 R2 2.85 100k 76.8k 2.9 100k 75.0k 3.0 100k 69.8k 3.1 100k 66.5k 3.15 100k 64.9k 3.3 100k 60.4k 3.45 100k 56.2k 3.525 93.1k 51.1k 3.6 100k 52.3k 3.8 100k 48.7k 4.0 100k 45.3k 4.1 100k 43.2k Resistor Value Table for the MIC29512 Adjustable Regulator May 2006 8 M9999-051706 (408) 955-1690 Micrel, Inc. MIC29510/29512 Package Information 3-Pin TO-220 (T) 5-Pin TO-220 (T) May 2006 9 M9999-051706 (408) 955-1690 Micrel, Inc. MIC29510/29512 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. © 1997 Micrel, Incorporated. May 2006 10 M9999-051706 (408) 955-1690