This application relates to the field of
switching power supply technology and discloses a
gallium nitride (GaN) charger based on a 494 PWM
chip. The charger includes a power board, a
rectifier circuit module, a half-bridge GaN driver module, a
transformer, a 494
chip control module, a totem-pole driver module, an isolation driver
transformer, a full-wave
rectifier module, a filter circuit module, and a conversion circuit module. The core of this application is that the 494
chip control module generates a PWM
signal, which is then amplified by the totem-pole driver module and electrically isolated and coupled by the isolation driver
transformer before driving two GaN transistors in the half-bridge topology to switch alternately at
high frequency. This application fully utilizes the high-speed switching characteristics of GaN devices, enabling the charger to operate at higher frequencies. This increases the
power level to the kilowatt level while reducing switching losses and the size of
magnetic components, achieving
high power density and high overall conversion efficiency.