High-power totem pole PFC controller enables code-free designs

Onsemi has introduced a new high-power totem pole PFC (TP-PFC) controller that reduces development time and cost. Joining the NCP1680, which is suited for designs up to 350 W, the new NCP1681 extends the power capability into the kilowatt range, targeting ultra-high-density offline power supplies.

The NCP1681 is designed to drive the bridgeless totem-pole PFC topology. This topology eliminates the diode bridge used at the input of a conventional PFC circuit, allowing significant improvement in the power stage efficiency, said onsemi.

TP-PFC designs typically require an MCU that added design complexity and the need for coding, said onsemi, but with the NCP1681, it doesn’t require coding and only a few external components are needed for a fully-featured TP-PFC solution.

The NCP1681 can be configured to work in either fixed frequency continuous conduction mode (CCM) or multi-mode operation, where the controller transitions between CCM and critical conduction mode (CrM) for optimal performance across power levels, said the company.

The NCP1681 is suited to higher-power power supplies from 350 W to several kilowatts that operate on universal mains input (90 – 265 VAC). This makes them suitable for a wide range of applications including servers, high performance computing, telecom, industrial, and OLED TVs. At high line, the NCP1681 TP-PFC solutions will achieve close to 99% efficiency. These devices can meet efficiency standards such as 80Plus and CoC Tier 2.

The NCP1681 and NCP1680 will be showcased at APEC 2022 at onsemi’s booth #1124. Other devices such as SiC MOSFETs and isolated gate drivers that can be used for the fast leg of the totem pole also will be showcased at the show.