MIC69303 Evaluation Board Single Supply VIN, Low VIN, Low VOUT, 3A LDO General Description The MIC69303 is a 3A output current member of the MIC69xxx family of high current, low voltage regulators. The MIC69303 operates from an input voltage of 1.65V to 5.5V and is designed to drive digital circuits requiring low voltage at high currents (i.e., PLDs, DSP, microcontroller, etc.). These regulators are available in adjustable and fixed output voltages. The adjustable version can support output voltages down to 0.5V. The µCap design of the MIC69303 is optimized for stability with low value, low-ESR ceramic output capacitors. Features of the MIC69303 include thermal shutdown and current limit protection. Logic enable and error flag pins are also available. The MIC69303 is offered in a low-profile, 12-Pin 4mm x 4mm MLFTM package. It is also available in an ePad SOIC-8 package. Both packages have an operating temperature range of –40°C to +125°C. Data sheets and support documentation can be found on Micrel’s web site at: www.micrel.com. Requirements The MIC69303 evaluation board requires a single power supply to provide VIN. The VIN power supply must be able to deliver 1.65V to 5.5V with more than 3A capability. The output load can either be an active or passive load. Precautions may damage the device. In addition, the maximum VIN operating voltage of the MIC69303 evaluation board is 5.5V. Exceeding 5.5V on VIN could permanently damage the device. Getting Started 1. Connect an external supply to VIN terminal. Apply desired input voltage to the VIN and ground terminals of the evaluation board, paying careful attention to polarity and supply voltage. An ammeter may be placed between the input supply and the VIN terminal to the evaluation board. Ensure that the supply voltage is monitored at the VIN terminal. The ammeter and/or power lead resistance can reduce the voltage supplied to the input. 2. Connect the load to the VOUT and ground terminals. The load can be either passive (resistive) or active (as in an electronic load). An ammeter can be placed between the load and the VOUT terminal. Ensure that the output voltage is monitored at the VOUT terminal. The VOUT can be adjusted by changing the feedback resistors. See “Output Voltage” section. 3. Enable the MIC69303. The EN pin is provided on the evaluation board with a 10k pull-up resistor. The output of the MIC69303 may be turned off by shorting the EN pin to ground. An external connection on the board provides easy access to the enable pin. Removing the pull-up resistor and leaving the EN pin floating will cause the regulator to operate in an indeterminate state. The evaluation board does not have reverse polarity protection. Applying a negative voltage to the VIN terminal Ordering Information Part Number Description Package MIC69303YML EV Evaluation board featuring the 3A MIC69303YML 12-Pin 4mm x 4mm MLF® MLF and MicroLeadFrame are registered trademarks of Amkor Technology, 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 M9999-050411-B Micrel, Inc. MIC69303YML EV (connected from ADJ to ground). The output voltage can easily be modified by removing R1 and RFB and replacing them with the values that would yield the desired output voltage. Once R1 is selected, RFB can be calculated using: Applications Information Output Voltage The output voltage on the MIC69303 evaluation board is adjustable. The output is set by connecting one of the feedback resistors (R4, R5, R6, or R7) into the circuit via a jumper short. The output voltage can be programmed to 1.5V, 1.8V, 2.5V, or 3.3V. The output voltage for the MIC69303 evaluation board is set at the factory for a 2.5V output. In general, the output voltage can be calculated using the following equation: where VREF May 2011 RFB = R1 × VREF VOUT − VREF RFB = R1 VOUT − 0.5V For VREF = 0.5V: R1 VOUT = VREF × (1 + ) RFB = 0.5V and RFB is the feedback resistor 2 M9999-050411-B Micrel, Inc. MIC69303YML EV Evaluation Board Schematic MIC69303YML Evaluation Board ® 12-Pin 4mm x 4mm MLF (J1 is for test purposes only) May 2011 3 M9999-050411-B Micrel, Inc. MIC69303YML EV Bill of Materials Item Part Number GRM219R61A105KC01D C1 C2 TDK(3) 0805ZD105KAT2A (4) AVX 0805ZD106KAT2A AVX(4) GRM21BR60J106ME19 GRM31CR60J476ME19L 12066D476MAT2A C6 R1 ------------CRCW06031001F Description Qty. Murata(2) C2012X5R1A105K C3216X5R0J476M C4,C5 Manufacturer Murata(2) TDK(3) Murata(2) AVX(4) ------ 1µF/10V Ceramic Capacitor, X5R, 0805 1 10µF/10V Ceramic Capacitor, X5R, 0805 1 47µF/6.3V Ceramic Capacitor, X5R, Size 1206 (greater or lesser capacitance value or larger case size OK) Large value electrolytic capacitor DNP DNP (1) 1.0kΩ Film Resistor, Size 0603, 1% 1 (1) Vishay R2 CRCW06031002F Vishay 10.0kΩ Film Resistor, Size 0603, 1% 1 R3 CRCW06031002F 10.0kΩ Film Resistor, Size 0603, 1% 1 R4 CRCW06034990F Vishay(1) Vishay(1) 499Ω Film Resistor, Size 0603, 1% 1 R5 CRCW06033830F Vishay(1) 383Ω Film Resistor, Size 0603, 1% 1 R6 CRCW06032490F Vishay(1) 249Ω Film Resistor, Size 0603, 1% 1 (1) CRCW06031780F Vishay 178Ω Film Resistor, Size 0603, 1% 1 CRCW060300R0F Vishay(1) 0Ω Film Resistor, Size 0603, 1% 1 R9 CRCW06031500F Vishay(1) 150Ω Film Resistor, Size 0603, 1% 1 U1 MIC69303YML 3A Low VIN, Low VOUT, Single-Supply LDO 1 R7 R8 Micrel, Inc.(5) Notes: 1. Vishay: www.vishay.com. 2. Murata: www.murata.com. 3. TDK: www.tdk.com. 4. AVX: www.avx.com. 5. Micrel, Inc.: www.micrel.com. May 2011 4 M9999-050411-B Micrel, Inc. MIC69303YML EV Evaluation Board PCB Layout MIC69303YML Evaluation Board – Top Layer May 2011 5 M9999-050411-B Micrel, Inc. MIC69303YML EV Evaluation Board PCB Layout (Continued) MIC69303YML Evaluation Board – Bottom Layer May 2011 6 M9999-050411-B Micrel, Inc. MIC69303YML EV 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. © 2010 Micrel, Incorporated. May 2011 7 M9999-050411-B