Introduction

Input bridge rectifier losses, found in nearly all AC/DC power supplies, pose a challenge in achieving high efficiency. Under such circumstances, the method of bridgeless totem pole PFC is attracting interest.

In this scheme, the bridge rectifier diodes of the AC power supply are replaced with active switches to take on the roles of the boost transistors and boost diodes in a conventional boost PFC, as shown in the figure below.

In addition, in this active switch, the SiC MOSFET is used for the high-speed switching leg, and the silicon MOSFET is used for the AC line.

The NCP1680 is a CrM (critical mode) PFC controller IC designed to drive bridgeless totem-pole PFC topologies.

Also for the NCP1681 is a PFC controller IC designed to drive bridgeless totem-pole PFC topologies.
It can be configured to operate in continuous conduction mode (CCM) or multimode (CrM-CCM).

The functions and circuit examples of each product are as follows.

Functions/features

·totem pole PFCs Topology eliminates input diode bridge, allowing for very high efficiency and compact design
・ AC line supervisor and AC Phase detection
・Brown-out detection
・ PFCOKMore indicator
・Almost in all operating modes 1 power factor of
·package
    NCP1680: SOIC-16
    NCP1681: SOIC-20

Safety function

・Soft and fast overvoltage protection
・OVP and OTPs for 2 Level latch input
・Bulk undervoltage protection
・Internal thermal shutdown
・Cycle-by-cycle current limit

application

·Cloud / server power
・ 5G/ telecom power
・Industrial power supply
Such

lastly

If you would like to know more about our totem pole PFC controller ICs, NCP1680 and NCP1681, please feel free to contact us.
In addition, ONSEMI can propose the most suitable products not only for the totem pole PFC method, but also for various control methods such as LLC, quasi-resonance, etc. in ACDC design.

Inquiry / Quotation

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