Click here for production status of specific part numbers. Evaluates: MAXM17623 1.5V MAXM17623 1.5V Output Output-Voltage Application Evaluation Kit General Description Quick Start The MAXM17623 1.5V output evaluation kit (EV kit) pro- Recommended Equipment vides a proven design to evaluate the MAXM17623 high One 2.9V to 5.5V DC, 1A power supply frequency, high-efficiency, synchronous step-down DC-DC One resistive load with 1.5V, 1A sink capacity power module. The EV kit is programmed to deliver 1.5V output for loads up to 1A. The EV kit features selectable One digital multimeter (DMM) mode, and open-drain PGOOD signal. The MAXM17623 MAXM17623EVKIT data sheet provides a complete description of the module that should be read in conjunction with this EV kit data Equipment Setup and Test Procedure sheet prior to modifying the demo circuit. For full module The EV kit is fully assembled and tested. Follow the steps features, benefits and parameters, refer to the MAXM17623 below to verify the board operation. data sheet. Caution: Do not turn on power supply until all connections are completed. Features 1) Set the power supply at a voltage between 2.9V and Highly Integrated Solution 5.5V. Then, disable the power supply. 2.9V to 5.5V Input Range 2) Connect the positive terminal of the power supply to Programmed 1.5V Output, Delivers Up To 1A the VIN PCB pad and the negative terminal to the Output Current nearest PGND PCB pad. Connect the positive ter- High 90.3% Efficiency minal of the 1A load to the VOUT PCB pad and the (V = 5V, V = 1.5V at 0.4A) negative terminal to the nearest PGND PCB pad. IN OUT 2MHz Switching Frequency 3) Connect the DVM (DMM in voltage-measurement mode) across the VOUT PCB pad and the nearest PFM Feature for Better Light-Load Efficiency PGND PCB pad. Fixed Internal 1ms Soft-Start Time 4) Verify that shunt is installed in the default position on PGOOD Output, with Pullup Resistor to V IN jumper J1 (see Table 1 for details). Overcurrent and Overtemperature Protection 5) Turn on the DC power supply. (OCP and OTP) 6) Enable the load. Low-Profile, Surface-Mount Components 7) Verify that the DVM displays 1.5V. Proven PCB Layout Fully Assembled and Tested Ordering Information appears at end of data sheet. 319-100300 Rev 2 1/20Evaluates: MAXM17623 1.5V MAXM17623 1.5V Output Evaluation Kit Output-Voltage Application Hot-Plug-In and Long Input Cables Detailed Description The MAXM17623 EV kit PCB provides an optional The MAXM17623 EV kit is designed to demonstrate Tantalum capacitor (C2, 47F/8V) to dampen input volt- salient features of MAXM17623 power module. The EV age peaks and oscillations that can arise during hot- kit includes an EN PCB pad, and jumper J1, to enable plug-in and/or due to long input cables. This capacitor the output. Jumper J2 allows selection of either PWM or limits the peak voltage at the input of the MAXM17623 PFM mode of operation based on light-load performance power module, when the EV kit is powered directly from a requirements. An additional PGOOD pad is available for precharged capacitive source or an industrial backplane monitoring if the converter output voltage is in regulation. PCB. Long input cables, between input power source and Output Capacitor Selection the EV kit circuit can cause input-voltage oscillations due X7R ceramic output capacitors are preferred due to their to the inductance of the cables. The equivalent series stability over temperature in industrial applications. The resistance (ESR) of the Tantalum capacitor helps damp required output capacitor (C4) for 1.5V output is selected out the oscillations caused by long input cables. Further, from Table 1 of the MAXM17623 data sheet as 22F/6.3V. capacitor C1 (0.1F/100V), placed near the input of the board, helps in attenuating high frequency noise. Adjusting Output Voltage Mode of Operation The MAXM17623 supports an adjustable output-voltage range, from 0.8V to 1.5V, using a feedback resistive divid- The MAXM17623 features PFM mode of operation to er from V to FB. Output voltage can be programmed increase the efficiency at light-load condition. If the MODE OUT using the values given in Table 1 of the MAXM17623 data pin is left unconnected during powerup, the module oper- sheet. For 1.5V output, R1 is chosen as 33.2k, and R2 ates in PFM mode at light loads. If the MODE pin is con- is chosen as 37.4k. nected to SGND during power-up, the part operates in constant-frequency PWM mode at all loads. See Table 2 Input Capacitor Selection for J2 settings. The input capacitor serves to reduce the current peaks drawn from the input power supply and reduces switching frequency ripple at the input. The input capacitance must be greater than or equal to the value given in Table 1 of the MAXM17623 data sheet. Input capacitor C3 is chosen to be 2.2F/10V. Table 1. Enable/Disable Configuration (J1) POSITION EN PIN MAXM17623 OUTPUT 1-2* Connected to V Enabled if V is greater than V IN IN EN-HIGH. 2-3 Connected to SGND Disabled *Default position Table 2. Mode of Operation (J2) POSITION MODE PIN 1-2 Operates in PWM mode at all load conditions. Not Installed* Operates in PFM mode at light-load conditions. *Default position Maxim Integrated 2 www.maximintegrated.com