A innovative current sensor-less continuous conduction mode PFC control

For PFC working under discontinues conduction or critical conduction modes, input current sensing is not required when constant on time control is applied. However, this approach cannot be extended to PFC working under continues conduction mode. In this paper, a innovative input current sensor-less control scheme has been proposed for PFC working under continuous conduction mode. Its value in digitally controlled PFC is great since high resolution and high bandwidth current sampling A/D can be eliminated. The nonideal effects in input current sensor-less control have also been analyzed in this paper. The proposed PFC control has been verified by our experimental prototype.