Click here for production status of specific part numbers. Evaluates: MAX17631 MAX17631C5EVKIT 5V Output-Voltage Application Evaluation Kit General Description Quick Start The MAX17631C5EVKIT evaluation kit (EV kit) pro- Recommended Equipment vides a proven design to evaluate the MAX17631C high- MAX17631C5EVKIT Evaluation Kit efficiency, synchronous step-down DC-DC converter. The 6.5V to 36V, 1.5A DC-input power supply EV kit provides 5V/1.5A at the output from a 6.5V to 36V input supply. The switching frequency of the EV kit is pre- Load capable of sinking 1.5A set to 400kHz for optimum efficiency and component size. Digital voltmeter (DVM) The EV kit features adjustable input undervoltage lock- out, adjustable soft-start, open-drain RESET signal, and Equipment Setup and Test Procedure external clock synchronization. The EV kit also provides The EV kit is fully assembled and tested. Follow the steps a good layout example, which is optimized for conducted, below to verify the board operation. radiated EMI, and thermal performance. For more details Caution: Do not turn on power supply until all con- about the IC benefits and features, refer to the MAX17631 nections are completed. IC data sheet. 1) Set the power supply at a voltage between 6.5V and 36V. Then, disable the power supply. Features Operates from a 6.5V to 36V Input Supply 2) Connect the positive terminal of the power supply to the VIN PCB pad and the negative terminal to the 5V Output Voltage nearest PGND PCB pad. Connect the positive termi- Delivers Up to 1.5A Output Current nal of the 1.5A load to the VOUT PCB pad and the 400kHz Switching Frequency negative terminal to the nearest PGND PCB pad. Enable/UVLO Input, Resistor-Programmable UVLO 3) Connect the DVM across the VOUT PCB pad and Threshold the nearest PGND PCB pad. Adjustable Soft-Start Time 4) Verify that shunts are installed across pins 1-2 on jumper JU1 (see Table 1 for details) and pins 2-3 on Open-Drain RESET Output jumper JU2 (see Table 2 for details) Overcurrent and Overtemperature Protection 5) Turn on the DC power supply. Proven PCB Layout 6) Enable the load. Fully Assembled and Tested 7) Verify that the DVM displays 5V. Complies with CISPR22(EN55022) Class B Conducted and Radiated Emissions Ordering Information appears at end of data sheet. 319-100377 Rev 0 5/19Evaluates: MAX17631 MAX17631C5EVKIT Evaluation Kit 5V Output-Voltage Application For example, in order to program a 1ms soft-start time, C3 Detailed Description should be 5600pF. The EV kit is designed to deliver 5V at load current up to 1.5A at the output from a 6.5V to 36V input supply. The Enable/Undervoltage-Lockout (EN/UVLO) switching frequency of the EV kit is configured at 400 kHz Programming by leaving RT resistor open. The MAX17631 offers an Enable and adjustable input The EV kit includes an EN/UVLO PCB pad and jumper undervoltage lockout feature. In this EV kit, for normal JU1 to enable the output at a desired input voltage. The operation, leave the EN/UVLO jumper (JU1) open. When MODE/SYNC PCB pad and jumper JU2 allow an external JU1 is left open, the MAX17631 is enabled when the clock to synchronize the device. Jumper JU2 allows the input voltage rises above 6.4V. To disable the MAX17631, selection of the mode of operation based on light load- install a jumper across pins 23 on JU1. See Table 1 performance requirements. An additional RESET PCB for JU1 settings. The EN/UVLO PCB pad on the EV kit pad is available for monitoring whether the converter supports external Enable/Disable control of the device. output is in regulation or not. Leave JU1 open when external Enable/Disable control is desired. A potential divider formed by R1 and R2 sets Soft-Start Input (SS) the input voltage (VINU) above which the converter is The EV kit offers an adjustable soft-start function to limit enabled when JU1 is left open. inrush current during the startup. The soft-start time is Choose R1 to be 3.32M (max), and then calculate R2 adjusted by the value of external soft-start capacitor (C3) as follows: connected between SS and SGND. The selected output capacitance (C ) and the output voltage (V ) deter- SEL OUT R1 1.215 mine the minimum value of C3, as shown by the following R2 = (V 1.215) equation: INU -6 C3 28 x 10 x C x V SEL OUT where, V is the voltage at which the device is required INU The soft-start time (t ) is related to the soft-start capaci- SS to turn on, and R1 and R2 are in k, tor C3 by the following equation: For more details about setting the undervoltage lockout C3 t = level, refer to the MAX17631 data sheet. SS -6 5.55 10 ( ) Table 1. Converter EN/UVLO Jumper (JU1) Settings SHUNT POSITION EN/UVLO PIN MAX17631C OUTPUT 1-2 Connected to VIN Enabled Connected to the center node of Enabled, UVLO level is set by the Not installed* resistor-divider R1 and R2 resistor-divider between VIN and SGND 2-3 Connected to SGND Disabled *Default position. Maxim Integrated 2 www.maximintegrated.com