MIC47050 Evaluation Board 500mA ULDO™ with Low Input and Output Voltages General Description Getting Started The MIC47050 is a high-speed, ultra-low dropout, dualsupply NMOS ULDO™ designed to take advantage of point-of-load applications that use multiple supply rails to generate a low-voltage, high-current power supply. The MIC47050 can source 500mA of output current while only requiring a 1µF ceramic output capacitor for stability. A 1.5% output voltage accuracy, low dropout voltage (44mV @ 500mA), and low ground current makes this device ideally suited for mobile applications. The MIC47050 has an NMOS output stage offering very low output impedance. The NMOS output stage makes for a unique ability to respond very quickly to sudden load changes such as that required by a microprocessor, DSP or FPGA. An input capacitor may be required when the power supply is more than 4-inches from the device. The evaluation board includes an input capacitor of 10μF to compensate for long inductive test leads. 1. Connect an external supply to VBIAS. Apply the (+) output of the bias power supply to the VBIAS (J3) terminal and the (-) output to the ground terminal (J2) of the evaluation board, paying careful attention to polarity and supply voltage (2.3V ≤ VBIAS ≤ 5.5V). An ammeter may be placed between the input supply and the VBIAS terminal of the evaluation board. Ensure that the supply voltage is monitored at the VBIAS terminal. 2. Connect an external supply to VIN. Apply the (+) output of the input power supply to the VIN (J1) terminal and the (-) output to the ground terminal (J2) of the evaluation board, paying careful attention to polarity and supply voltage (1.0V ≤ VIN ≤ 3.6V and VIN ≤ VBIAS). An ammeter may be placed between the input supply and the VIN terminal of the evaluation board. Ensure that the supply voltage is monitored at the VIN terminal. The ammeter and power lead resistance can reduce the voltage supplied to the input. Requirements The MIC47050 evaluation board requires two power supplies, one to provide a minimum of 500mA to VIN and the other to provide the VBIAS voltage. The BIAS pin, requiring relatively light current, provides power to the control portion of the MIC47050. The input voltage range for the BIAS pin is 2.3V to 5.5V. To avoid VBIAS-to-VOUT dropout, the minimum VBIAS voltage should be 2.3V or 1.25V (typically) above VOUT, whichever is greater. The evaluation board is provided with a 0.1µF capacitor from BIAS-to-ground to help reduce high frequency noise from being injected into the control circuitry. 3. Enable/Disable the MIC47050. The evaluation board is configured for “Default Enable” with a 20kΩ pull up resistor on the enable pin to VBIAS. To disable the MIC47050, apply a logic low voltage to the EN terminal (J6). The enable pin must be either pulled high or low for proper operation. 4. Connect the load to the VOUT terminals. Apply the load across the VOUT (J4) and ground terminals (J5). The load can be either passive (resistor) or active (electronic load). Be sure to monitor the output voltage at the VOUT (J4) terminal. Precautions The evaluation board does not have reverse polarity protection. Applying a negative voltage to any terminal may damage the device. Ordering Information Part Number Description MIC47050YML EV Adjustable MIC47050 Evaluation Board MIC47050YMT EV Adjustable MIC47050 Evaluation Board 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 February 5, 2014 Revision 1.1 Micrel, Inc. MIC47050 Evaluation Board Evaluation Board Schematic Bill of Materials Item Part Number GRM188R60J106ME47D Murata C1608X5R0J106M TDK C1 06036D106MAT2A Capacitor, 10µF Ceramic, 6.3V, X5R, Size 0603 Capacitor, 10µF Ceramic, 10V, X5R, Size 0603 AVX Murata TDK GRM188R60J105KE19D C3 C1608X5R0J105M 0603ZC105MAT CRCW060310K0FKEYE3 (1) 1 Capacitor, 0.1µF Ceramic, 25V, X5R, Size 0603 (2) Capacitor, 0.1µF Ceramic, 25V, X5R, Size 0603 (3) Capacitor, 0.1µF Ceramic, 25V, X7R, Size 0603 AVX Murata Qty. Capacitor, 10µF Ceramic, 6.3V, X5R, Size 0603 (3) C1608X5R1E104M 06033C104MAT Description (1) (2) GRM188R61E104KA01D C2 R1 Manufacturer (1) 1 Capacitor, 1.0µF Ceramic, 6.3V, X5R, Size 0603 (2) Capacitor, 1.0µF Ceramic, 6.3V, X5R, Size 0603 (3) Capacitor, 1.0µF Ceramic, 10V, X5R, Size 0603 TDK AVX 1 (4) Resistor, 10kΩ,1/16W, 1%, Size 0603 (4) Resistor, 4.99kΩ, 1/16W, 1%, Size 0603 1 (4) Resistor, 20kΩ, 1/16W, 1%, Size 0603 1 Vishay R2 CRCW06034K99FKEYE3 Vishay R3 CRCW060320K0FKEYE3 Vishay U1 MIC47050YML Micrel (5) 500mA ULDO™ Adjustable VOUT, 2mm x 2mm MLF 1 ® 1 Notes: 1. Murata: www.murata.com. 2. TDK: www.tdk.com. 3. AVX: www.avx.com. 4. Vishay: www.vishay.com. 5. Micrel, Inc.: www.micrel.com. February 5, 2014 2 Revision 1.1 Micrel, Inc. MIC47050 Evaluation Board PCB Layout Recommendations Top Layer Bottom Layer February 5, 2014 3 Revision 1.1 Micrel, Inc. MIC47050 Evaluation Board 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. 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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. February 5, 2014 4 Revision 1.1