BD9C401EFJ-EVK-001 ROHM

Switching Regulator Series Step-Down DC/DC Converter BD9C401EFJ Evaluation Board BD9C401EFJ-EVK-001 Description This evaluation board has been developed for ROHMs synchronous buck DC/DC converter customers evaluating BD9C401EFJ. While accepting a power supply of 4.72-18V, an output of 3.3V can be produced. The IC has internal 65m high-side P-channel MOSFET and 35m low-side N-channel MOSFET and a synchronization frequency is of 500kHz. A Soft Start circuit prevents in-rush current during startup. An EN pin allows for simple ON/OFF control of the IC to reduce standby current consumption. Include OCP (Over Current Protection) and SCP (Short Circuit Protection). Evaluation Board Operating Limits and Absolute Maximum Ratings (Ta=25) Limit Parameter Symbol Unit Conditions MIN TYP MAX (NOTE1) Supply Voltage V 4.5 - 18 V CC V - 3.3 - V OUT Output Voltage / Current I - - 4 A OUT (NOTE1) When the output voltage is 3.3V, it is 4.72V by limiting ratio of the maximum duty. Evaluation Board Figure 1. BD9C401EFJ-EVK-001 Evaluation Board www .rohm.com 9 December 2014 Rev.002 2014 ROHM Co., Ltd. All rights reserved. 1/8 BDD9C401EFFJ-EVK-0001 Opperation Proocedures 1. NNecessary equipments (1) DC power-supply of 4.77V to 18V/4A (2) Maximumm 4A load (3) DC voltmeeter 2. CConnecting thhe equipmentss (1) DC power-supply preseets to 12V andd then the powwer output turnns off. (2) The max. load should bbe set at 4A annd over it will bbe disabled. (3) Check Jumper pin of SW1 is short, bbetween intermmediate-terminnal and OFF-sside terminal. (4) Connect ppositive-terminnal of power-ssupply to VIN++terminal and negative-termminal to GND-teerminal with aa pair of wires.. (5) Connect lloads positivee-terminal to VVOUT+terminaal and negativee-terminal to GGND-terminal with a pair of wires. (6) Connect ppositive-terminnal of DC voltmmeter 1 to TP1 and negative-terminal to TTP2 for input-vvoltage measuurement. (7) Connect ppositive-terminnal of DC voltmmeter 2 to TP33 and negative-terminal to TTP4 for outputt-voltage measurement. (8) DC power-supply outpuut is turned ONN. (9) IC is enabble (EN) by shhorting Jumper-pin of SW1 bbetween intermmediate-terminal and ON-siide terminal. (10) Check DDC voltmeter 22 displays 3.3VV. (11) The loadd is enabled. (12) Check aat DC voltmeteer 1 whether thhe voltage-droop (loss) is nott caused by thhe wires resisttance. - DC Voltmeter 2 V - + V DDC Voltmeter 1 - + Load + - DC Powwer + Figure 22. Connection Diagram Ennable-Pin To minimizee current conssumption durinng standby-moode and normmal operation, Enable-mode can be switchhed by controllling EN pin(6pin)) of the IC. SStandby-modee is enabled by shorting Jumper-pin oof SW1 betweeen intermediate-terminal and OFF-side terminal and norrmal-mode opeeration by shoorting betweenn intermediate-terminal and ON-side termminal. It aalso can be swwithed betweeen standby-moode and normmal-mode operration by remooving Jumper--pin and contrrolling the volttage bettween EN andd GND-terminaal. Standby-mmode is enableed when the vvoltage of EN is under 0.8VV, and normal-mode operaation when it is over 2.0V. wwww.rohm.com 99 Decemberr 2014 Rev.0002 22014 ROHM Coo., Ltd. All rights reserved. 2/8