STMICROELECTRONICS STCMB1

STCMB1 is a transition mode PFC with X-cap discharge and LLC resonant combo controller. The PFC section uses a proprietary constant on-time control methodology that does not require a sinusoidal input reference, thereby reducing the system cost and external component count. It includes also a complete set of protections: a cycle-by-cycle OCP, an output OVP, a feedback failure, an AC brown-out, boost inductor saturation and inrush current detection both at the start-up and after mains sags or missing cycles. The half-bridge (HB) section provides two complementary outputs that drive the high-side and low-side MOSFET 180° out-of-phase. The deadtime inserted between the turn-off of an either switch and the turn-on of the other is automatically adjusted to ensure zero voltage switching and higher efficiency from low to full load. A proprietary control method, time shift control - TSC, improves dynamic behaviour and input ripple rejection resulting in a cleaner output voltage.