onsemi introduced its latest mixed-signal controller dedicated to bridgeless totem-pole PFC (TP PFC) topology. The  NCP1681targets ultra-high-density offline power supplies. Building upon the success of the NCP1680, which is suited for designs up to 350 W, the new controller extends the power capability into the kilowatt range.

In the past, TP PFC designs required the use of an MCU that added design complexity and the need for coding. However, with the NCP1681, only a few external components and no coding is needed to be added for a fully-featured TP PFC solution, thereby saving time, cost and space.

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

The new NCP1681 high-power TP PFC controller integrates established control algorithms with novel features to deliver a high-performance and cost-effective TP PFC solution. Challenging efficiency standards such as ‘80Plus’ or ‘CoC Tier 2’, that require high efficiency over a wide load range, can also be met.

The new NCP1681 is suited to higher-power power supplies from 350 W to several kilowatts range that operates on universal mains input (90 – 265 Vac), addressing a wide range of applications including server, high-performance computing, telecom, industrial and OLED TV. At the high line, NCP1681 TP PFC solutions will achieve close to 99% efficiency.

The NCP1681 will be demonstrated alongside the award-winning lower power (<300 W) NCP1680 at  APEC 2022, at the George R. Brown Convention Center in Houston, TX. The demonstrations can be found at onsemi’s booth (1124) from March 21 to March 23.