Abstract
Buck power factor correction (PFC) converter is widely used for a broad range of AC/DC applications because of its many advantages like protection against short circuit, high efficiency at universal input voltage, low output voltage, less voltage stress on the switch, low inrush current and low component cast. However the inherent dead zone introduces a large harmonic distortion in the average input current, which results a low power factor (PF) and high total harmonic distortion (THD). A constant on-time controlled critical conduction mode (CRM) buck-buck/boost converter is introduced in this paper. It can obtain high PF. The operational principle of the buck and buck-buck/boost converter is discussed and the effectiveness of the topology is evaluated by simulation results.