Date: 09/04/2022

99% effeciency achievable TP PFC power controller runs MCU-free

The new mixed-signal controller NCP1681 from onsemi supports bridgeless totem pole PFC (TP PFC) power conversion topology for highly dense offline power supplies. This chip follows earlier NCP1680, which was designed to handle power up to 350 W. NCP1681 can enable power handling in kilowatt range for applications including server, high performance computing, telecom, industrial and OLED TV.

"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 controller can be configured to operate in Continuous Conduction Mode (CCM) or Multi-Mode (CrM-CCM) operation." is the brief explanation of concept of TP PFC by ONSEMI.

The NCP1681 is configurable to switch between fixed frequency continuous conduction mode (CCM) or multi-mode operation, where the controller switches to CCM and critical conduction mode (CrM) on its own based on the output power load.

By using this new device designers can develop TP PFC designs without the use of a microcontroller and only a few external components for a fully-featured TP PFC solution saving coding-time, cost and other complexities. The NCP1681 TP PFC solutions can deliver close to 99% efficiency, and can fulfill efficiency standards such as ‘80Plus’ or ‘CoC Tier 2’

Robert Tong, Senior Vice President & General Manager of Computing and Cloud Division at onsemi said “The new NCP1681 extends the benefits of code-free TP PFC design into higher power. This allows our customers to continue to enhance the efficiency of their design while reducing design time and cost, thereby delivering solutions to market quickly.”