High power factor constant current buck-boost power converter with floating IC driver control

摘要

A high power factor, constant current, buck-boost LED driver circuit is provided with floating IC driving control. A DC power supply is provided with a first input and a second input that is coupled to a mains ground. A switching circuit is coupled to receive the first input and to convert input power into a constant current supply for an LED load. A current sensor is coupled to the switching circuit and configured to provide feedback signals representative of a current through the LED load, and a controller is coupled to the switching circuit and the current sensor and configured to provide driver signals to the switching circuit based at least in part on the feedback signal. Each of the switching circuit, the current sensor and the controller are commonly coupled to a floating circuit ground. A buck-boost inductor is further coupled between the floating ground and mains circuit ground.