onsemi NCP1681 Totem-Pole Power Factor Controller is a PFC controller optimized for driving the bridgeless totem-pole PFC topology. The bridgeless totem-pole PFC is a power factor correction architecture that consists of a fast switching leg driven at the PWM switching frequency and a second leg that operates at the AC line frequency. This topology eliminates the diode bridge present at the input of a conventional PFC circuit, allowing significant improvement in the power stage efficiency. The NCP1681 Controller can be configured to operate in continuous conduction mode (CCM) or multi-mode (CrM-CCM) operation. The onsemi NCP1681 Totem-Pole Power Factor Controller is housed in a SOIC-20 package.