TIDU312A May 2014 – November 2020
The function of a PFC stage is to convert the AC mains voltage to a regulated DC bus voltage while drawing a sine wave input current. Typically, this is implemented using a bridge rectifier followed by a boost PFC stage. However, to reduce the power losses in the diode bridge and to improve the system efficiency an alternative approach is to use a bridgeless system and implement both the rectification and power factor control using two boost stages. In this approach the two boost stages are operated alternately in the positive and negative half cycles of the ac mains voltage. A C2000 microcontroller with its on-chip PWM and ADC modules is able to implement complete digital control of such bridgeless PFC (BL PFC) system.