The UCC28880 integrates the controller and a 700-V power MOSFET into one monolithic device. The device also integrates a high-voltage current source, enabling start up and operation directly from the rectified mains voltage. The low quiescent current of the device enables excellent efficiency. With the UCC28880 the most common converter topologies, such as buck, buck-boost and flyback can be built using a minimum number of external components. The UCC28880 incorporates a soft-start feature for controlled start up of the power stage which minimizes the stress on the power-stage components.