BD9328EFJEVK-101 ROHM

ROHM Switching Regulator Solutions Evaluation Board: Step-down Switching Regulator With Built-in Power MOSFET No.0000000014 BD9328EFJ / BD9329AEFJ (12V 2A / 3A Output) Introduction This application note will provide the steps necessary to operate and evaluate ROHMs step-down switching regulator using the BD9328EFJ/BD9329AEFJ evaluation boards. Component selection, board layout recommendations, operation procedures and application data is provided. Description This evaluation board has been developed for ROHMs step-down switching regulator customers evaluating BD9328EFJ and/or BD9329AEFJ. While accepting a wide power supply of 4.2-18V, a step down output of 3.3V or any external resistor defined voltage can be produced. The ICs have two integrated low resistance N-channel MOSFETs and a fixed synchronization frequency of 380 kHz. A Soft Start circuit prevents in-rush current during startup along with UVLO (low voltage error prevention circuit) and TSD (thermal shutdown detection) protection circuits. An EN pin allows for simple ON/OFF control of the IC to reduce standby current consumption. Applications Distributed Power Systems Pre-regulator for linear regulators Evaluation Board Operating Limits and Absolute Maximum Ratings Limit Parameter Symbol Unit Conditions MIN TYP MAX Supply Voltage BD9328EFJ VCC 4.2 12 18 V BD9329AEFJ VCC 4.2 12 18 V Output Voltage / Current BD9328EFJ VOUT - 3.3V - V BD9329AEFJ VOUT - 3.3V - V BD9328EFJ IOUT - - 2 A BD9329AEFJ IOUT - - 3 A Evaluation Board Below is the evaluation board with the BD9328EFJ. BD9329AEFJ eval board uses the same components and board layout Vout Vin High E N Low 1 Application Note Evaluation Board Schematic Below is the evaluation board schematic for BD9328EFJ. BD9329AEFJ eval board uses the same schematic Evaluation Board I/O Below is the reference application circuit that shows the inputs (Vin and EN) and the output (SW and FB) Evaluation Board Operation Procedures Below is the procedure to operate the evaluation board 1. Connect GND to a GND pin on the evaluation board 2. Connect Vin to the +12V Vin pin. This will provide Vin to the Vin pin of the IC i. Note: EN pin is pulled high as when SW1 is high (white arrow) 3. Now output power can be measured from the +3.3V Vout pin on the evaluation board with a load attached Page 2 of 9