Click here for production status of specific part numbers. MAX17671FEVKIT Evaluates: MAX17671 5V Step-Down Evaluation Kit Converter and 3.3V Linear Regulator Output Voltage Application General Description Benefits and Features The MAX17671F evaluation kit (EV kit) is a fully assem- 6.5V to 60V Input-Voltage Range for the Step-Down bled and tested circuit board that demonstrates the Converter performance of the MAX17671F dual-output regulator 5V Step-Down Converter Output Voltage, Up To integrating a high-efficiency, high voltage, fixed output 150mA Continuous Load Current voltage, synchronous step-down DC-DC converter, and 3.3V Linear Regulator Output Voltage, Up To 50mA a high-PSRR, low-noise, fixed-output linear regulator. Continuous Load Current The EV kit is designed for a high efficiency solution, and Peak Efficiency of 90% for the Step-Down Converter generates a 5V step-down converter output voltage and a fixed 3.3V linear regulator output voltage at load cur- 70A No-Load Supply Current rents up to 150mA and 50mA, respectively. When the 200kHz Switching Frequency linear regulator output is loaded, the step-down converter Internal Soft-Start output current is reduced by I , where I is the LDO LDO load current on the linear regulator output. The EV kit EN/UVLO Input, Resistor-Programmable UVLO draws only 70A supply current under no-load conditions. Threshold The step-down converter is programmed to a switch- MODE/SYNC Pin to Select PWM or PFM Mode ing frequency of 200kHz and delivers a peak efficiency Open-Drain RESET Output to Monitor Dual Outputs of 90% with the supplied components. The dual-output device is simple to use and easily configurable with External Frequency Synchronization minimal external components. The EV kit features adjust- Overcurrent and Overtemperature Protection able input undervoltage lockout, open-drain RESET sig- Proven PCB Layout nal, hysteretic peak current-limit protection and external frequency synchronization. Fully Assembled and Tested Ordering Information appears at end of data sheet. 319-100220 Rev 0 7/18MAX17671FEVKIT Evaluates: MAX17671 5V Step-Down Evaluation Kit Converter and 3.3V Linear Regulator Output Voltage Application 6.5V to 60V and the input of the linear regulator is con- Quick Start nected to the output of the step-down converter. The EV Required Equipment kit is designed for a high efficiency solution, and gener- MAX17671FEVKIT ates a 5V step-down converter output voltage and a fixed 3.3V linear regulator output voltage at load currents up to 6.5V to 60V, 200mA DC-input power supply 150mA and 50mA, respectively. When the linear regulator Two loads capable of sinking 150mA and 50mA output is loaded, the step-down converter output current Two digital voltmeters (DVM) is reduced by I , where I is the load current on the LDO LDO linear regulator output. The EV kit draws only 70A sup- Procedure ply current under no-load conditions. The step-down con- The EV kit is fully assembled and tested. Follow the steps verter is programmed to a switching frequency of 200kHz below to verify board operation. Caution: Do not turn on and delivers a peak efficiency of 90% with the supplied the power supply until all connections are completed. components. The dual-output device is simple to use and 1) Set the power supply at a voltage between 6.5V and easily configurable with minimal external components. 60V. Disable the power supply. The EV kit features adjustable-input undervoltage lockout, open-drain RESET signal, hysteretic peak current-limit 2) Connect the positive terminal of the power supply protection and external frequency synchronization. to the VIN PCB pad and the negative terminal to the nearest GND PCB pad. Connect the positive This EV kit includes an EN/UVLO PCB pad and JU1 to terminal of the 150mA load to the VOUT PCB pad enable the step-down converter output at a desired input and the negative terminal to the nearest GND PCB voltage. The MODE/SYNC PCB pad and JU2 are pro- pad. Connect the positive terminal of the 50mA load vided for selecting the intended mode of operation and to the OUTL PCB pad and the negative terminal to to allow an external clock to synchronize the step-down the nearest GND PCB pad. converter. A RESET PCB pad is available for monitoring the RESET output. 3) Connect the DVMs across the VOUT PCB pad and the nearest GND PCB pad, and across the OUTL Setting the Input EN/UVLO Level PCB pad and the nearest GND PCB pad. The device offers an adjustable-input undervoltage lock- 4) Verify that the jumper JU1 is open (see Table 1). out level. Set the voltage at which the device turns on 5) Select the shunt position on the jumper JU2 accord- with a resistive voltage-divider connected from IN to GND. ing to the intended mode of operation (see Table 2). Connect the center node of the divider to EN/UVLO as shown in Figure 1. Choose R1 to be 3.3M and then 6) Turn on the DC power supply. calculate R2 as follows: 7) Enable the loads. If linear regulator output is not loaded, step-down converter output can be loaded R1 1.215 R2 = up to 150mA. Else, it can be loaded up to (150 - (V 1.215) INU I )mA, where I is the load current on the LDO LDO linear regulator output in mA. where V is the voltage above which the device is INU required to turn on. The allowed minimum value of V 8) Verify that the DVMs display 5V and 3.3V. INU is 4V. See Table 1 for proper jumper settings. 9) Vary the input voltage from 6.5V to 60V, and vary the load currents on step-down converter and linear regulator outputs, and verify that the output voltages of step-down converter and linear regulator are 5V V IN IN and 3.3V, respectively. R1 MAX17671F Detailed Description The MAX17671F evaluation kit (EV kit) is a fully assem- EN/UVLO bled and tested circuit board that demonstrates the R2 performance of the MAX17671F dual-output regulators integrating a high-efficiency, high voltage, fixed output GND voltage, synchronous step-down DC-DC converter, and a high-PSRR, low-noise, fixed output linear regulator. The step-down converter operates over a wide input range of Figure 1. Setting the Input-Undervoltage Lockout Maxim Integrated 2 www.maximintegrated.com