CASCADE BOOST AND INVERTING BUCK CONVERTER WITH INDEPENDENT CONTROL

摘要

A converter system including a cascade boost converter and inverting buck converter and controller for converting a rectified AC voltage to a DC output current. The system uses inductors and is configured to use a common reference voltage. The controller is configured to control switching of the converters in an independent manner to decouple operation from each other. For example control pulses for the boost converter may be wider than pulses for the buck converter. The controller may control the boost converter based on constant on-time control and may control the inverting buck converter based on peak current control. The rectified AC voltage may be an AC conductive angle modulated voltage where the controller may inhibit switching of the inverted buck converter at a dimming frequency having a duty cycle based on a phase angle of the AC conductive angle modulated voltage.