A BIFRED CONVERTER AND A METHOD OF DRIVING AN OUTPUT LOAD

摘要

A boost integrated flyback (BiFRED) converter which has a current sensing element (R2) in series with the energy storage device (C1) of the converter for sensing a boost portion current and a discharging flyback portion current. A feedback circuit (54) processes the sensed current to derive a control signal which is then used for adjusting the time duration for which the switching element (S1) of the BiFRED converter is switched on based on the control signal. This arrangement makes use of primary side current sensing to modify standard on-time control so that the current ripple in the output can be suppressed.