Evaluates: MAX17541G in 5V MAX17541G 5V Output Output-Voltage Application Evaluation Kit General Description Quick Start The MAX17541G 5V Output EV kit provides a proven Recommended Equipment design to evaluate the MAX17541G 5V high-efficiency, MAX17541G 5V Output EV kit high-voltage, synchronous step-down DC-DC converter. 6V to 42V, 2A DC input power supply The EV kit generates 5V at load currents up to 500mA from a 6V to 42V input supply. The EV kit features a Load capable of sinking 500mA 600kHz fixed switching frequency for optimum efficiency Digital voltmeter (DVM) and component size. The EV kit features a forced-PWM Function generator control scheme that provides constant switching-frequency operation at all load and line conditions. Procedure The EV kit is fully assembled and tested. Follow the steps Features below to verify the board operation. Caution: Do not turn Operates from a 6V to 42V Input Supply on power supply until all connections are completed. 5V Output Voltage 1) Set the power supply at a voltage between 6V and 500mA Output Current 42V. Disable the power supply. 600kHz Switching Frequency 2) Connect the positive terminal of the power supply to the VIN PCB pad and the negative terminal to the Enable/UVLO Input nearest PGND PCB pad. Connect the positive terminal Resistor-Programmable UVLO Threshold of the 500mA load to the VOUT PCB pad and the Open-Drain RESET Output negative terminal to the nearest PGND PCB pad. Overcurrent and Overtemperature Protection 3) Connect the DVM across the VOUT PCB pad and the nearest PGND PCB pad. Proven PCB Layout 4) Turn on the DC power supply. Fully Assembled and Tested 5) Enable the load. 6) Verify that the DVM displays 5V. Ordering Information appears at end of data sheet. To turn-on/off the part from EN/UVLO, follow the steps below: 1) Connect the power supply to the EV kit and turn on the power supply. Set the power supply at a voltage between 6V and 42V. 2) Connect the function generator output to the EN/UVLO test loop. 3) EN/UVLO rising threshold is 1.24V and falling threshold is 1.11V. Make sure that the voltage-high and voltage-low levels of the function generator output are greater than 1.24V and less than 1.11V, respectively. 4) While powering down the EV kit, first disconnect the function generator output from the EN/UVLO test loop and then turn off the DC power supply. 19-7723 Rev 0 7/15MAX17541G 5V Output Evaluates: MAX17541G in 5V Evaluation Kit Output-Voltage Application Setting the Undervoltage-Lockout Level Detailed Description of Hardware The device offers an adjustable input undervoltage- The MAX17541G 5V Output EV kit provides a proven lockout level. Set the voltage at which the device turns design to evaluate the 5V high-efficiency, high-voltage, on with a resistive voltage-divider connected from VIN synchronous step-down DC-DC converter. The EV kit to GND (see Figure 1). Connect the center node of the generates 5V at load currents up to 500mA from a 6V to 42V divider to EN/UVLO. input supply. The EV kit features a 600kHz fixed switching frequency for optimum efficiency and component size. The Choose R1 to be 3.3M and then calculate R2 as follows: EV kit features a forced-PWM control scheme that provides R1 1.218 constant switching-frequency operation at all load and line R2 = conditions. (V 1.218) INU The EV kit includes an EN/UVLO PCB pad to enable where V is the voltage at which the device is required control of the converter output. An additional RESET INU to turn on. Ensure that V is higher than 0.8 x V . PCB pad is available for monitoring the open-drain logic INU OUT output. The VCC PCB pad helps measure the internal Adjusting the Output Voltage LDO voltage. The device offers an adjustable output voltage. Set the Soft-Start Input (SS) output voltage with a resistive voltage-divider connected from the positive terminal of the output capacitor (V ) The device utilizes an adjustable soft-start function to OUT to GND (see schematic attached to this PDF). Connect limit inrush current during startup. The soft-start time is the center node of the voltage-divider to FB. adjusted by the value of C3, the external capacitor from SS to GND. To adjust the soft-start time, determine C3 To choose the values of R4 and R5, select the parallel using the following formula: combination of R4 and R5, with R less than 15k. Once P R is selected, calculate R4 as follows: C3 = 5.55 x t P SS where t is the required soft-start time in milliseconds SS RV P OUT and C3 is in nanofarads. R4 = 0.9 Regulator Enable/Undervoltage-Lockout Calculate R5 as follows: Level (EN/UVLO) The device features an EN/UVLO input. For normal R4 0.9 operation, no shunts should be installed across pins 1-2 R5 = (V 0.9) OUT or 2-3 on jumper JU1. To disable the output, install a shunt across pins 2-3 on JU1 and the EN/UVLO pin is pulled to GND. See Table 1 for JU1 settings. Table 1. Regulator Enable (EN/UVLO) Jumper JU1 Settings SHUNT POSITION EV/UVLO PIN MAX17541G 5V OUTPUT Connected to the center node of resistor-divider Enabled, UVLO level set through the R1 and R2 Not installed* R1 and R2 Resistor-divider 2-3 Connected to GND Disabled *Default position. Maxim Integrated 2 www.maximintegrated.com