| Abstract |
In addition to Transition Mode (TM) and Fixed-Frequency Continuous Conduction Mode (FF-CCM)
operation of PFC pre-regulators a third approach is proposed that couples the simplicity and affordability
of TM operation with the high-current capability of FF-CCM operation: it is a peak currentmode
control with fixed-OFF-time (FOT control). Its basic characteristics and the benefits brought to
PFC pre-regulators will be highlighted and weighed against the drawbacks. Then, with a simplified
design-oriented analysis, a large-signal model will be identified. Based on this result, a step-by-step
design procedure will be outlined and a real design example will be considered that demonstrates the
technique. Finally, the bench evaluation results of the prototyped design example will be presented. |
