Click here for production status of specific part numbers. Evaluates: MAXM17900 MAXM17900 Evaluation Kit 5V Output-Voltage Application General Description Quick Start The MAXM17900 evaluation kit (EV kit) is a demon- Recommended Equipment stration circuit of the MAXM17900 ultra-small, high effi - MAXM17900EVKIT , MAXM17900 evaluation kit ciency, current mode, synchronous step-down DC-DC 24V DC power supply switching power module. The EV kit operates over an input-voltage of 10V to 24V and provides up to Dummy load capable of sinking 100mA 100mA load current with a 5V output voltage. The EV Digital voltmeter (DVM) kit is programmed to switch at a frequency of 600kHz. 100MHz dual-trace oscilloscope The module is simple to use and easily configurable with minimal external components. It features cycle-by- Procedure cycle peak current-limit protection, undervoltage lockout The MAXM17900 EV kit is fully assembled and tested. (EN/UVLO), and thermal shutdown. Please follow the steps below to verify the board opera- The EV kit comes with the compact 10-pin 2.6mm x tion. Caution: Do not turn on the power supply until all 3mm x 1.5mm uSLIC package MAXM17900 module connections are completed. installed, and is rated to operate over the full industrial/ 1) Set the power supply at a voltage between 10V and automotive -40C to +125C temperature range. For full 24V. Disable the power supply. specifications, features and benefits of the IC, refer to the 2) Connect the positive and negative terminals of the MAXM17900 data sheet. power supply to VIN and GND PCB pads, respectively. Features 3) Connect the positive and negative terminals of the Wide 10V to 24V Input 100mA load to VOUT and GND PCB pads respec- tively, and the set the load to 0A. 1.75% Feedback Voltage Accuracy 4) Connect the DVM across the VOUT PCB pad and the Output: 5V,100mA GND PCB pad closest to VOUT PCB pad. Internally Compensated 5) Enable the input power supply. All Ceramic Capacitors and Ultra-Compact Solution 6) Verify the DVM across output display 5V. PFM or Force-PWM Mode of Operation 7) Increase the load up to 100mA to verify the output Shutdown Current as Low as 1.2A (typ) voltage is 5V using DVM. Programmable Soft-Start and Prebias Startup Open-Drain Power Good Output (RESET pin) Programmable EN/UVLO Threshold Ordering Information appears at end of data sheet. Hiccup Overcurrent Protection (OCP) Overtemperature Protection (OTP) uSLIC is a trademark of Maxim Integrated Products, Inc. -40C to +125C Industrial/Automotive Temperature Range Complies with CISPR22 (EN55022) Class B Conducted and Radiated Emissions Passes Drop, Shock, and Vibration Standards JESD22B103, B104, B111 319-100075 Rev 1 8/18Evaluates: MAXM17900 MAXM17900 Evaluation Kit 5V Output-Voltage Application operates in a constant-frequency forced-PWM mode at Detailed Description of Hardware all loads. The mode of operation cannot be changed on- The MAXM17900 EV kit is a proven circuit to demonstrate the fly during normal operation of the device. Refer to the the high-voltage, high-efficiency, and compact solution MAXM17900 module datasheet for more information on size of the MAXM17900 synchronous step-down DC-DC the PWM and PFM modes of operation. Table 1 shows power module. The output voltage is preset to 5V to the EV kit jumper settings that can be used to configure operate from 10V to 24V input and provides up to 100mA the desired mode of operation. load current. The optimal frequency is set at 600kHz to maximize efficiency and minimize component size. The External Synchronization (RT/SYNC) EV kit includes two test points, TP1 for monitoring the LX The RT/SYNC pin can be used to synchronize modules and TP2 for measuring the RESET voltage. internal oscillator to an external system clock. Refer to the External Synchronization section in the MAXM17900 Soft-Start Input (SS) data sheet for additional information on configuring the The module offers a fixed 5.1ms internal soft-start when external clock synchronization. the SS pin is left unconnected. When adjustable soft-start time is required, connect a capacitor from SS to GND to Reset Output (RESET) program the soft-start time. The minimum soft-start time is The module includes an open-drain RESET output to related to the output capacitance (C ) and the output OUT monitor output voltage. RESET should be pulled up with voltage (V ) by the following equation: OUT an external resistor to the desired external power supply t > 0.05 x C x V less than or equal to 5.5V. RESET goes high-impedance SS OUT OUT 2ms after the output rises above 95% of its nominal set where t is in milliseconds and C is in F. SS OUT value and pulls low when the output voltage falls below Soft-start time (t ) is related to the capacitor connected SS 92% of the set nominal output voltage. RESET asserts low at SS (C ) by the following equation: 3 during the hiccup timeout period. In this EV kit, R7 resistor C = 6.25 x t 3 SS can be used to pull up the RESET to the output voltage. where t is in ms and C is in nF. SS 3 Table 1. Mode Configuration (J1) Mode Selection (MODE) MAXM17900 The device features a MODE pin for selecting either POSITION MODE PIN OPERATION forced-PWM or PFM mode of operation. If the MODE pin 1-2 Connected to GND PWM mode is left unconnected, the device operates in PFM mode Not Installed Open PFM mode at light loads. If the MODE pin is grounded, the device Maxim Integrated 2 www.maximintegrated.com