Click here for production status of specific part numbers. Evaluates: MAX17670 3.3V Step-Down MAX17670EEVKIT Converter Output Voltage and 3.0V Linear Evaluation Kit Regulator Output Voltage Application General Description Benefits and Features The MAX17670E evaluation kit (EV kit) is a fully assem- 4.5V to 60V Input-Voltage Range for the Step-Down bled and tested circuit board that demonstrates the Converter performance of the MAX17670E dual-output regulator 3.3V 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 3.0V Linear Regulator Output Voltage, Up To 20mA a high-PSRR, low-noise, fixed-output linear regulator. Continuous Load Current The EV kit is designed for a high efficiency solution. Peak Efficiency of 90.6% for the Step-Down The EV kit generates a 3.3V step-down converter output voltage and a fixed 3.0V linear regulator output voltage Converter at load currents up to 150mA and 20mA, respectively. 70A No-Load Supply Current When the linear regulator output is loaded, the Step- 200kHz Switching Frequency down converter output current is reduced by I , where LDO Internal Soft-Start I is the load current on the linear regulator output. LDO The EV kit draws only 70A supply current under no-load EN/UVLO Input, Resistor-Programmable UVLO conditions. The step-down converter is programmed to Threshold a switching frequency of 200kHz and delivers a peak MODE/SYNC Pin to Select PWM or PFM Mode efficiency of 90.6% with the supplied components. The Open-Drain RESET Output to Monitor Dual Outputs dual-output device is simple to use and easily configurable with minimal external components. The EV kit features External Frequency Synchronization adjustable input undervoltage lockout, open-drain RESET Overcurrent and Overtemperature Protection signal, hysteretic peak current-limit protection and external Proven PCB Layout frequency synchronization. Fully Assembled and Tested Ordering Information appears at end of data sheet. 319-100284 Rev 0 12/18Evaluates: MAX17670 3.3V Step-Down MAX17670EEVKIT Evaluation Kit Converter Output Voltage and 3.0V Linear Regulator Output Voltage Application connected to the output of the step-down converter. The Quick Start EV kit is designed for a high efficiency solution. The EV Required Equipment kit generates a 3.3V step-down converter output voltage MAX17670EEVKIT and a fixed 3.0V linear regulator output voltage, at load currents up to 150mA and 20mA, respectively. When 4.5V to 60V, 200mA DC-input power supply the linear regulator output is loaded, the step-down con- Two loads capable of sinking 150mA and 20mA verter output current is reduced by I , where I LDO LDO Two digital voltmeters (DVM) is the load current on the linear regulator output. The Procedure EV kit draws only 70A supply current under no-load conditions. The step-down converter is programmed to The EV kit is fully assembled and tested. Follow the steps a switching frequency of 200kHz and delivers a peak below to verify board operation. Caution: Do not turn on efficiency of 90.6% with the supplied components. The the power supply until all connections are completed. dual-output device is simple to use and easily con- 1) Set the power supply at a voltage between 4.5V and figurable with minimal external components. The EV kit 60V. Disable the power supply. features adjustable-input undervoltage lockout, open- 2) Connect the positive terminal of the power sup- drain RESET signal, hysteretic peak current-limit protec- ply to the VIN PCB pad and the negative terminal tion and external frequency synchronization. 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 20mA load vided for selecting the intended mode of operation and to the OUTL PCB pad and the negative terminal to the to allow an external clock to synchronize the step-down nearest GND PCB pad. converter. A RESET PCB pad is available for monitoring 3) Connect the DVMs across the VOUT PCB pad and the RESET output. the nearest GND PCB pad, and across the OUTL PCB pad and the nearest GND PCB pad. Setting the Input EN/UVLO Level 4) Verify that the jumper JU1 is open (see Table 1). The device offers an adjustable-input undervoltage lock - 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 6) Turn on the DC power supply. shown in Figure 1. Choose R1 to be 3.3M and then 7) Enable the loads. If linear regulator output is not load- calculate R2 as follows: ed, step-down converter output can be loaded up to 150mA. Else, it can be loaded up to (150 - I )mA, R1 1.215 LDO R2 = where I is the load current on the linear regulator LDO (V 1.215) INU output in mA. where V is the voltage above which the device is INU 8) Verify that the DVMs display 3.3V and 3.0V. required to turn on. The allowed minimum value of V INU 9) Vary the input voltage from 4.5V to 60V, and vary is 4V. See Table 1 for proper jumper settings. 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 3.3V and 3.0V, respectively. VIN IN Detailed Description R1 MAX17670E The MAX17670E evaluation kit (EV kit) is a fully assem- EN/UVLO bled and tested circuit board that demonstrates the performance of the MAX17670E dual-output regulators R2 integrating a high-efficiency, high voltage fixed output voltage, synchronous step-down DC-DC converter, and a GND high-PSRR, low-noise, fixed output linear regulator. The step-down converter operates over a wide input range Figure 1. Setting the Input-Undervoltage Lockout of 4.5V to 60V and the input of the linear regulator is Maxim Integrated 2 www.maximintegrated.com