ADP1047-300-EVALZ: 300W PFC, 385V Out, 85 ~ 265V in

This evaluation board features the ADP1047 in a typical AC/DC switching power supply in a boost power factor correction (PFC) topology. The circuit is designed to provide a rated load of 385V/300W from an AC input voltage source of 85 VRMS to 265 VRMS AC. The ADP1047 provides functions all the functions necessary for active PFC circuit plus accurate AC power metering. It achieves near-unity power factor, low distortion of the input current, the output voltage regulation, over current protection, AC line fault detection and protection, over temperature protection, and power supply shutdown. It also can optimize light load efficiency performance using output voltage adjustment and frequency reduction.

Please refer to the appendix for the detailed schematic. The AC input side consists of the input terminals, EMI filter, inrush relay and its control circuit. The D1 is the rectifier bridge for main power transmission. The D4 is used for input voltage sensing. The boost circuit consists boost inductor (L2), boost switch (Q1) and diode (D2). The gate signal for the boost switch comes from the ADP1047 through the ADP3634 gate driver. The ADP1047 (U1, on daughter card) can be powered either via the USB 5V via an ADP3303 LDO (U2, on daughter card) present on the same daughter card, or via the auxiliary power supply on the board. Thermistor (RTD1) is placed close to the MOSFET on the board allowing over temperature protection functionality to be implemented.