Click here for production status of specific part numbers. Evaluates: MAX17662 in MAX17662BEVKITA 3.3V Output-Voltage Application Evaluation Kit General Description Quick Start The MAX17662BEVKITA evaluation kit (EV kit) provides Recommended Equipment a proven design to evaluate the MAX17662B high- MAX17662BEVKITA efficiency, synchronous step-down DC-DC converter. 4.5V to 36V, 2A DC-input power supply The EV kit provides 3.3V/2A at the output from a 4.5V to 36V input supply. The switching frequency of the EV kit is Load capable of sinking 2A preset to 500kHz for optimum efficiency and component One digital voltmeter (DVM) size. The EV kit features adjustable input undervoltage lockout, adjustable soft-start, open-drain RESET signal. Equipment Setup and Test Procedure The EV kit layout is optimized for thermal performance. The EV kit is fully assembled and tested. Follow the steps For more details about the IC benefits and features, refer below to verify the board operation. to MAX17662B data sheet. Caution: Do not turn on power supply until all connections are completed. Features 1) Set the power supply at a voltage between 4.5V and Operates from a 4.5V to 36V Input Supply 36V. Then, disable the power supply. 3.3V Output Voltage 2) Connect the positive terminal of the power supply Delivers Up to 2A Output Current to the VIN PCB pad and the negative terminal to 500kHz Switching Frequency the nearest PGND PCB pad. Connect the positive terminal of the 2A load to the VOUT PCB pad and Enable/Undervoltage Lockout Input, Resistor- the negative terminal to the nearest PGND PCB pad. Programmable UVLO Threshold 3) Connect the DVM across the VOUT PCB pad and Adjustable Soft-Start Time the nearest PGND PCB pad. Open-Drain RESET Output 4) Verify that shunts are installed across pins 1-2 on Overcurrent and Overtemperature Protection jumper JU1 (see Table 1 for details) Proven PCB Layout 5) Select the shunt position on JU2 according to the Fully Assembled and Tested intended mode of operation (see Table 2 for details) 6) Turn on the DC power supply. 7) Enable the load. 8) Verify that the DVM displays 3.3V. Ordering Information appears at end of data sheet. 9) Verify that the DVM displays at RESET PCB pad is 1.8V. 319-100428 Rev 1 9/19Evaluates: MAX17662 in MAX17662BEVKITA Evaluation Kit 3.3V Output-Voltage Application Enable/Undervoltage-Lockout Detailed Description (EN/UVLO) Programming The MAX17662BEVKITA EV kit is designed to deliver The MAX17662B offers an enable and adjustable input load current up to 2A at 3.3V output voltage from a 4.5V undervoltage lockout feature. In this EV kit, for normal to 36V input supply. The switching frequency of the EV kit operation, leave EN/UVLO jumper (JU1) open. When is configured at 500kHz by leaving the RT resistor open. JU1 is left open, the MAX17662B is enabled when the The EV kit includes an EN/UVLO PCB pad and jumper input voltage rises above 4.3V. To disable MAX17662B, JU1 to enable the output at a desired minimum input install a jumper across pins 2-3 on JU1. See Table 1 voltage. Jumper JU2 allows the selection of the mode of for JU1 settings. The EN/UVLO PCB pad on the EV kit operation based on light load-performance requirements. supports external enable/disable control of the device. An additional RESET PCB pad is available for monitoring Leave jumper JU1 open when external enable/disable whether the converter output is in regulation. control is desired. A potential divider formed by R1 and R2 Soft-Start Input (SS) sets the input voltage (V ) above which the converter is INU enabled when JU1 is left open. The EV kit offers an adjustable soft-start function to limit inrush current during the startup. The soft-start time Choose R1 to be 3.32M max, and then calculate R2 as is adjusted by the value of C3, the external capacitor follows: connected between SS and SGND. The selected output capacitance (C ) and the output voltage (V ) R1 1.25 SEL OUT R2 = determine the minimum value of C3, as shown by the V 1.25 ( ) INU following equation: -6 C3 28 x 10 x C x V SEL OUT where, The soft-start time (t ) is related to the soft-start capacitor SS V is the voltage at which the device is required to turn on. INU C3 by the following equation: R1 and R2 are in k, C3 For more details about setting the input undervoltage t = SS 6 lockout level, refer to the MAX17662B data sheet. 8.325 10 ( ) For example, to program a 0.82ms soft-start time, C3 should be 6800pF. Table 1. Converter EN/UVLO Jumper (JU1) Settings SHUNT POSITION EN/UVLO PIN MAX17662B OUTPUT 1-2 Connected to V Always enabled IN Connected to the center node of resistor-divider Enabled, UVLO level is set by the Not installed* R1 and R2 resistor-divider between V and SGND IN 2-3 Connected to SGND Disabled *Default position. Maxim Integrated 2 www.maximintegrated.com