2017 ROHM Co., No. 60AP001E Rev.001 Ltd. 2017. 4 User s Guide Switching Regulator Series Step-Down DC/DC Converter BD9C301FJ Evaluation Board BD9C301FJ-EVK-001 BD9C301FJ-EVK-001 Evaluation board delivers an output 3.3 volts from an input 4.5 to 18 volts using BD9C301FJ, a synchronous rectification step- down DC/DC converter integrated circuit, with output current rating of maximum 3A. The output voltage can be set by changing the external parts of circuit and the loop-response characteristics also can be adjusted by the phase compensation circuit. Performance specification These are representative values, and it is not a guaranteed against the characteristics. VIN = 12V, VOUT = 3.3V, Unless otherwise specified. Min Parameter Typ Max Units Conditions (NOTE1) Input Voltage Range 4.5 18 V Output Voltage 3.3 V R1=7.5k, R2=2.4k (NOTE2) Output Voltage Setting Range V 0.125 V 0.7 V IN IN Output Current Range 0 3.0 A Loop Band Width 39.8 kHz Phase Margin 56.2 degrees Input Ripple Voltage 120 mVpp IO = 3.0A Output Ripple Voltage 50 mVpp IO = 3.0A Output Rising Time 1 ms Operating Frequency 500 kHz Maximum Efficiency 91.4 % I = 1.2A O (NOTE1) When the output voltage is 3.3V, it is 4.72V by limiting ratio of the maximum duty. (NOTE2) However, (V 0.125) 0.8V IN 2014 ROHM Co., Ltd. No. 60UG008E Rev.003 1/9 APR.2017 BD9C301FJ-EVK-001 User s Guide Operation Procedures 1. Necessary equipment (1) DC power-supply of 4.7V to 18V/3A (2) Maximum 3A load (3) DC voltmeter 2. Connecting the equipment (1) DC power-supply presets to 12V and then the power output turns off. (2) The maximum load should be set at 3A and over it will be disabled. (3) Check Jumper pin of SW1 is short, between intermediate-terminal and OFF-side terminal. (4) Connect positive-terminal of power-supply to VIN+ terminal and negative-terminal to GND-terminal with a pair of wires. (5) Connect loads positive-terminal to VOUT+ terminal and negative-terminal to GND-terminal with a pair of wires. (6) Connect positive-terminal of DC voltmeter 1 to TP1 and negative-terminal to TP2 for input-voltage measurement. (7) Connect positive-terminal of DC voltmeter 2 to TP3 and negative-terminal to TP4 for output-voltage measurement. (8) DC power-supply output is turned ON. (9) IC is enable (EN) by shorting Jumper-pin of SW1 between intermediate-terminal and ON-side terminal. (10) Check DC voltmeter 2 displays 3.3V. (11) The load is enabled. (12) Check at DC voltmeter 1 whether the voltage-drop (loss) is not caused by the wires resistance. DC Voltmeter 2 V + DC Voltmeter 1 V + Load + DC Power + Figure 1. Connection Diagram Enable-Pin To minimize current consumption during standby-mode and normal operation, Enable-mode can be switched by controlling EN pin (6pin) of the IC. Standby-mode is enabled by shorting Jumper-pin of SW1 between intermediate-terminal and OFF-side terminal and normal-mode operation by shorting between intermediate-terminal and ON-side terminal. It also can be switched between standby-mode and normal-mode operation by removing Jumper-pin and controlling the voltage between EN and GND-terminal. Standby-mode is enabled when the voltage of EN is under 0.8V, and normal-mode operation when it is over 2.0V. 2014 ROHM Co., Ltd. No. 60UG008E Rev.003 2/9 APR.2017