The NCP1605 is a controller that exhibits near-unity power factor while operating in fixed frequency, Discontinuous Conduction Mode (DCM) or in Critical Conduction Mode (CRM). Housed in a SOIC-16 package, the circuit incorporates all the features necessary for building robust and compact PFC stages, with a minimum of external components. In addition, it integrates the skip cycle capability to lower the standby losses to a minimum.