Evaluates: MAX17681 for Isolated 15V MAX17681 Evaluation Kit or 12V Output Configuration General Description Quick Start The MAX17681 evaluation kit (EV kit) is a fully assembled Recommended Equipment and tested circuit board that demonstrates the performance One 15V to 60V DC, 0.5A power supply of the MAX17681 high-efficiency, iso-buck DC-DC converter. Two loads of 50mA to 100mA sink capacity The EV kit operates over a wide input voltage range of 17V to 32V and uses primary-side feedback to regulate Four digital multimeters (DMM) the output voltage. The EV kit has two output configura- Caution: Do not turn on the power supply until all tions. In the first configuration, the output is programmed to connections are completed. 15V at 100mA, with 10% output-voltage regulation. The second configuration uses a post regulator (MAX17651) to Procedure produce 12V at 50mA with < 3% regulation. The EV kit comes with default output configuration programmed to 15V. The EV kit comes installed with the MAX17681 in a 10-pin (3mm x 2mm) TDFN package and MAX17651 in a 6-pin Test Procedure for 15V Output TSOT package. 1) Verify that jumper JU1 is open. Features 2) Verify that the R17R19 are not installed. 17V to 32V Input Voltage Range 3) Set the power-supply output to 24V. Disable the power supply. 15V, 100mA or 12V, 50mA Continuous Current 4) Connect the positive terminal of the power supply to EN/UVLO Input the VIN PCB pad and the negative terminal to the 200kHz Switching Frequency nearest PGND PCB pad. Connect the positive terminal 90% Peak Efficiency of the first 100mA load to the +15V PCB pad and the negative terminal to the nearest GND0 PCB pad. Overcurrent Protection Connect the positive terminal of the second 100mA No Optocoupler load to the GND0 PCB pad and the negative terminal Delivers Up to 3W Output Power to the nearest -15V PCB pad. Overtemperature Protection 5) Connect a DMM configured in voltmeter mode across the +15V PCB pad and the nearest GND0 Proven PCB layout PCB pad. Connect another DMM configured in voltmeter mode across the -15V PCB pad and the nearest GND0 PCB pad. 6) Enable the input power supply. Ordering Information appears at end of data sheet. 7) Enable the loads and verify that the output voltage is at 15V with respect to GND. 8) If required, vary the input voltage from 17V to 32V, the load current from 0 to 100mA, and verify that the output voltage is 15V. 19-7634 Rev 2 2/17Evaluates: MAX17681 for Isolated 15V MAX17681 Evaluation Kit or 12V Output Configuration Test Procedure for 12V Output Detailed Description 1) Verify that JU1 is open. The EV kit is a fully assembled and tested circuit board that demonstrates the performance of the MAX17681 2) Remove R16 and R10. Place 0 resistors in R18 high-efficiency, iso-buck DC-DC converter designed to and R19. Place a 681k pack-out resistor (comes provide isolated power up to 3W. The EV kit generates with EV kit package) in R17. either 15V, 100mA or 12V, 50mA output voltages from 3) Set the power-supply output to 24V. Disable the a 17V to 32V input supply. The EV kit features a forced- power supply. PWM control scheme that provides constant switching- 4) Connect the positive terminal of the power supply frequency of 200kHz operation at all load and line conditions. to the VIN PCB pad and the negative terminal to The EV kit includes an EN/UVLO PCB pad to enable the nearest PGND PCB pad. Connect the positive control of the converter output. The VPRI PCB pad helps terminal of the first 50mA load to the +12V PCB pad measure the regulated nonisolated buck voltage. An and the negative terminal to the nearest GND0 PCB additional RESET PCB pad is available for monitoring pad. Connect the positive terminal of the second FB regulated voltage, the open-drain logic output. The 50mA load to the GND0 PCB pad and the negative programmable soft-start feature allows users to reduce terminal to the nearest -12V PCB pad. input inrush current. 5) Connect a DMM configured in voltmeter mode The iso-buck is a synchronous-buck-converter-based across the +12V PCB pad and the nearest GND0 topology, useful for generating isolated outputs at low PCB pad. Connect another DMM configured in power level without using an optocoupler. The detailed voltmeter mode across the -12V PCB pad and the procedure for setting the soft-start time, ENABLE/UVLO nearest GND0 PCB pad. divider, primary output-voltage (V ) selection, adjusting PRI the primary output voltage, primary inductance selection, 6) Enable the input power supply. turns-ratio selection, output capacitor selection, output 7) Enable the loads and verify that the output voltage is diode selection, and external loop compensation are at 12V with respect to GND. given in the MAX17681 IC data sheet. The post-regulator 8) If required, vary the input voltage from 17V to 32V, MAX17651 output-voltage setting and additional related the load current from 0 to 50mA, and verify that the information are detailed in the MAX17651 IC data sheet. output voltage is 12V. Enable Control (JU1) The EN/UVLO pin on the device serves as an on/off control while also allowing the user to program the input undervoltage-lockout (UVLO) threshold. JU1 configures the EV kits output for on/off control. Install a shunt across JU1 pins 2-3 to disable VOUT. See Table 1 for proper JU1 jumper configurations. Table 1. Enable Control (EN/UVLO) (JU1) Jumper Settings SHUNT POSITION EN/UVLO PIN VOUT OUTPUT 1-2 Connected to VIN Enabled 2-3 Connected to GND Disabled Open* Connected to midpoint of R1, R2 resistor-divider Enabled at VIN 15.5V *Default position. Component Suppliers SUPPLIER WEBSITE Wurth Electronik www.we-online.com Murata Americas www.murata.com Panasonic Corp. www.panasonic.com Note: Indicate that you are using the MAX17681 when contacting these component suppliers. Maxim Integrated 2 www.maximintegrated.com