ADP1853-EVALZ: 3.3V @ 20A, 9 ~ 15V in

This document describes the design, operation, and test results of the ADP1853-EVALZ. The input voltage range for this evaluation board is 9 V to 15 V, and the regulated output voltage VOUT is set to 3.3 V with the maximum output current up to 20 A. The switching frequency (fSW) of 300 kHz is set to achieve high efficiency.

The ADP1853 is a step-down switching controller with integrated drivers for N-channel synchronous power MOSFETs. The switching frequency of the ADP1853 can be synchronized to an external clock signal applied to the SYNC input. The ADP1853 has a clock output, CLKOUT, which can be used for synchronizing other controllers. The CLKOUT frequency is the same as the switching and it is 180° out of phase.

In addition, the boost diode is integrated into the ADP1853, thus lowering the overall system cost and component count. The ADP1853 can be set to operate in pulse skip, high efficiency mode (PSM) under light load, or in PWM continuous conduction mode.

The ADP1853 includes externally adjustable soft start, output overvoltage protection, externally programmable current limit, power good, tracking function, and a programmable oscillator frequency that ranges from 200 kHz to 1.5 MHz. The ADP1853 has the reference voltage accuracy of ±1% from −40°C to +125°C junction temperature.