Boundary Conduction Mode Controlled Power Factor Corrector With Line Voltage Recovery and Total Harmonic Distortion Improvement Techniques

The proposed line voltage recovery (LVR) and the total harmonic distortion improvement (THDI) technique improve power factor (PF) and total harmonic distortion (THD) over a wide line voltage range in boundary conduction mode controlled power factor corrector (PFC). The LVR detects the input line root-mean-square voltage to generate the digital equivalent code to the THDI for optimizing the THD by tuning the on-time value at different line voltages. In addition, the LVR and the THDI provide a feedforward path to reduce the ripple of the feedback voltage for further improving the THD. Therefore, the PFC controller can keep high PF and low THD over a wide line voltage. Experimental results demonstrate that the peak PF value is 0.998 and the minimum THD is 1.7% by the test circuit fabricated in a TSMC 800-V ultrahigh-voltage process with the universal line voltage range of 90-264 V.