1. Brief Introduction

PFC is a Power Factor Correction circuit that improves the power factor of a circuit and is commonly used in appliances over 100 W. The PFC circuit allows the current waveform to follow the voltage waveform, increasing the active power of the circuit and suppressing current harmonics.

LLC resonant circuit is a DC/DC circuit with high conversion efficiency, because its circuit contains resonant inductor Lr, excitation inductor Lm and resonant capacitor Cr, so it is called LLC circuit. LLC circuit can achieve soft switching of switching devices such as MOS tubes in the full load range, reducing the switching losses of switching devices and improving conversion efficiency, and is commonly used in 100-watt and kilowatt-level circuits.

▲ GD32E503R-SMPS PFC+LLC Board

2. Function Description

GD32E503R SMPS PFC+LLC board (hereinafter referred to as SMPS board) consists of PFC part and LLC part, PFC part is controlled by GD32E230C MCU, with 220V AC input and 415V DC output; LLC part is controlled by GD32E503R MCU, with 415V DC input and 24V DC output. The SMPS board provides peripheral resources such as SWD interface, USART debug port, buzzer and cooling fan, which can realize various protection functions such as overvoltage, undervoltage detection, overcurrent detection and overheat detection.

▲ System Block Diagram

3. Main Features

• Bridge PFC + half-bridge LLC topology, with a maximum efficiency of 500W

• High-voltage and low-voltage are controlled separately by dual MCUs, PFC is controlled by GD32E230C and LLC is controlled by GD32E503R.

• GD32E503R uses SHRTIMER to control the frequency of the LLC circuit with very high control accuracy

• PFC maximum efficiency of 95.40% with a maximum PF value of 1.00

• Maximum efficiency of the LLC circuit is 96.04% with <±1.5% ripple

• Maximum efficiency of the whole system is 90.85% with <±1.5% ripple

• Over-voltage, under-voltage, over-current, and over-temperature protection

4. Development Resources

GigaDevice can provide evaluation kits, user guides, hardware schematics, software code and other complete development materials. Please contact your local GigaDevice sales office or authorized representative for more details.

5. Typical Applications

Digital power supplies, outdoor power supplies, communication/server power modules, etc.