Evaluates: MAXM17502 in a 5V MAXM17502 5V Output Output-Voltage Application Evaluation Kit General Description Quick Start The MAXM17502 evaluation kit (EV kit) is a demonstration Recommended Equipment circuit of the MAXM17502 high-voltage, high-efficiency, MAXM17502 EV kit current mode, synchronous step-down DC-DC switching 60V DC power supply (V ) power module. The EV kit is designed to provide 5V IN with up to 1A load of current from a wide input-voltage Dummy load capable of sinking 1A range of 12V to 60V. The EV kit switches at an optimal Digital voltmeter (DVM) 540kHz switching frequency to allow for small component 100MHz dual-trace oscilloscope and solution sizes while maintaining high performance. The EV kit provides a precision-enable input and an Procedure open-drain RESET output signal to provide a simple and The EV kit is fully assembled and tested. Please follow reliable startup sequence. The EV kit also includes the steps below to verify board operation. Caution: Do optional component footprints to program different output not turn on the power supply until all connections are voltages, an adjustable input undervoltage-lockout, and a completed. soft-start time to control inrush current during startup. The 1) Set the power supply at a voltage between 12V and MAXM17502 module data sheet provides a complete 60V. Disable the power supply. description of the part and should be read in conjunction 2) Connect the positive and negative terminals of the with this evaluation kit data sheet prior to modifying the power supply to IN and PGND PCB pads, respectively. demo circuit. 3) Connect the positive and negative terminals of the 1A load to OUT and PGND2 PCB pads, respectively, Features and set the load to 0A. Highly Integrated Solution with an Integrated, 4) Connect the DVM across the OUT PCB pad and the Shielded Inductor PGND2 PCB pad. Wide 12V to 60V Input Range 5) Verify that no shunts are installed across pin 1-2 on Preset 5V Output Voltage jumper JU1 to enable UVLO (see Table 1 for details). 6) Enable the input power supply. Up to 1A Output Current 7) Verify the DVM display 5V. High Efficiency 84% (V = 24V, V = 5V at 1.0A) IN OUT 8) Increase the load up to 1A to verify the DVM continue 540kHz Switching Frequency displaying 5V. Enable/UVLO Input, Resistor-Programmable UVLO Threshold Adjustable Soft-Start Time Open-Drain RESET Output Internally Compensated Overcurrent and Overtemperature Protection Low-Profile, Surface-Mount Components Lead(Pb)-Free and RoHS Compliant Fully Assembled and Tested Ordering Information appears at end of data sheet. 319-100013 Rev 0 4/17Evaluates: MAXM17502 in a 5V MAXM17502 5V Output Evaluation Kit Output-Voltage Application Programmable Undervoltage-Lockout (UVLO) Detailed Description of Hardware The EV kit offers an adjustable input undervoltage-lockout The MAXM17502 EV kit is a proven circuit to demonstrate level by resistor dividers connecting between IN, EN/UVLO, the high-voltage, high-efficiency, and compact solution- and GND pins. For normal operation, a shunt should not size of the synchronous step-down DC-DC power module. be installed across pins 1-2 on JU1 to enable the output The output voltage is preset for 5V to operate from 12V through an external pull up 3.3M resistor from EN/UVLO to 60V and provides up to 1A load current. The optimal pin to IN pin. To disable the output, install the shunt across frequency is set at 540kHz to maximize efficiency and pins 1-2 on JU1 to pull EN/UVLO pin to GND. See Table 1 minimize component size. The EV kit includes JU1 to for JU1 setting details. The EV kit also provides an optional enable/disable UVLO of the device. The RESET PCB pad R56 PCB footprint to program a UVLO threshold voltage is also available for monitoring output voltage regulation at which an input voltage level device turns on. The R56 to enable or disable the application circuit of the load. The resistor can be calculated by the following equation: electrolytic capacitor (C51) is required only when the V IN power supply is situated far from the device circuit. 4019.4 R56 = (V 1.218) Soft-Start Input (SS) INU The device integrates a 10nF soft-start capacitor to limit where V is the input voltage at which the device is INU inrush current during startup. The minimum soft-start time required to turn on and R56 unit is in k. is 1.8ms. The soft-start time can be increased by connect- Setting V with a Resistive Voltage-Divider at FB OUT ing an additional capacitor (C ) from SS to GND. The SS The EV kit is preset for 5V and offers an adjustable output value of the additional capacitor can be calculated from voltage range as low as 0.9V and up to 5V at 1A maximum the desired soft-start as follows: load. The adjustable output voltage can be programmed C = (5.55 x t - 10) SS SS by the set of resistor-dividers R1 and R2. Refer to the where t is in ms and C is in nF. SS SS Components Selection Table of the MAXM17502 IC data sheet to select optimal component values for each specific input voltage range from 12V to 60V and an output voltage from 0.9V to 5V. To obtain an output voltage other than those provided in Table 1 of the MAXM17502 module data sheet, R1 and R2 need to be modified according to the equations described in Setting the Output Voltage section of the MAXM17502 data sheet. Table 1. UVLO Enable/Disable Configuration (JU1) SHUNT POSITION EN PIN MAXM17502 OUTPUT Installed Connected to GND Disable Not installed* Connected to VIN Enable *Default position. Maxim Integrated 2 www.maximintegrated.com