Click here for production status of specific part numbers. Evaluates: MAXM17624 3.3V MAXM17624 3.3V Output Output-Voltage Application Evaluation Kit General Description Quick Start The MAXM17624 3.3V output evaluation kit (EV kit) pro- Recommended Equipment vides a proven design to evaluate the MAXM17624 high One 3.6V to 5.5V DC, 1A power supply frequency, high-efficiency, synchronous step-down DC-DC One resistive load with 3.3V, 1A sink capacity power module. The EV kit is programmed to deliver 3.3V output for loads up to 1A. The EV kit features selectable One digital multimeter (DMM) mode, and open-drain PGOOD signal. The MAXM17624 MAXM17624EVKIT 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 MAXM17624 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 3.6V and Highly Integrated Solution 5.5V. Then, disable the power supply. 3.6V to 5.5V Input Range 2) Connect the positive terminal of the power supply to Programmed 3.3V 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 95.2% Efficiency minal of the 1A load to the VOUT PCB pad and the (V = 5V, V = 3.3V at 0.4A) negative terminal to the nearest PGND PCB pad. IN OUT 4MHz 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 3.3V. Proven PCB Layout Fully Assembled and Tested Ordering Information appears at end of data sheet. 319-100299 Rev 2 1/20Evaluates: MAXM17624 3.3V MAXM17624 3.3V Output Evaluation Kit Output-Voltage Application the MAXM17624 data sheet. Input capacitor C3 is chosen Detailed Description to be 2.2F/10V. The MAXM17624 EV kit is designed to demonstrate salient features of MAXM17624 power module. The EV Hot-Plug-In and Long Input Cables kit includes an EN PCB pad, and jumper J1, to enable The MAXM17624 EV kit PCB provides an optional the output. Jumper J2 allows selection of either PWM or Tantalum capacitor (C2, 47F/8V) to dampen input PFM mode of operation based on light-load performance voltage peaks and oscillations that can arise during requirements. An additional PGOOD pad is available for hot-plug-in and/or due to long input cables. This capacitor monitoring if the converter output voltage is in regulation. limits the peak voltage at the input of the MAXM17624 power module, when the EV kit is powered directly from a Output Capacitor Selection precharged capacitive source or an industrial backplane X7R ceramic output capacitors are preferred due to their PCB. Long input cables, between input power source and stability over temperature in industrial applications. The the EV kit circuit can cause input-voltage oscillations due required output capacitor (C4) for 3.3V output is selected to the inductance of the cables. The equivalent series from Table 1 of the MAXM17624 data sheet as 10F/16V. resistance (ESR) of the Tantalum capacitor helps damp Adjusting Output Voltage out the oscillations caused by long input cables. Further, capacitor C1 (0.1F/100V), placed near the input of the The MAXM17624 supports an adjustable output-voltage board, helps in attenuating high frequency noise. range, from 1.5V to 3.3V, using a feedback resistive divid- er from V to FB. Output voltage can be programmed OUT Mode of Operation using the values given in Table 1 of the MAXM17624 data The MAXM17624 features PFM mode of operation to sheet. For 3.3V output, R1 is chosen as 118k, and R2 is increase the efficiency at light-load condition. If the MODE chosen as 37.4k. pin is left unconnected during powerup, the module oper- Input Capacitor Selection ates in PFM mode at light loads. If the MODE pin is con- nected to SGND during power-up, the part operates in The input capacitor serves to reduce the current peaks constant-frequency PWM mode at all loads. See Table 2 drawn from the input power supply and reduces switching for J2 settings. frequency ripple at the input. The input capacitance must be greater than or equal to the value given in Table 1 of Table 1. Enable/Disable Configuration (J1) POSITION EN PIN MAXM17624 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