Highly Integrated, Compact Footprint

• Eliminates switching losses in InnoSwitch4 primary switch

• Captures and recycles leakage inductance energy

• Dramatically improves power supply efficiency

• Interfaces seamlessly with InnoSwitch4

• Powered directly from InnoSwitch4 BYPASS pin

• Self-biased at start-up

• Operates in both DCM and CCM modes

• Robust 750 V PowiGaN switch (CPZ1075M / CPZ1076M)

Advanced Protection / Safety Features

• Integrated temperature sensing and hysteretic thermal shutdown

Green Package

• Halogen free and RoHS compliant

Applications

• High density flyback designs up to 220 W

Description

The ClampZero™ IC pairs with the InnoSwitch™4 family of ICs to

eliminate energy wasted due to switching losses in the clamp and

primary switch. This dramatically improves power supply efficiency –

easily exceeding 95 - while maintaining the flexibility and low

component count of the flyback architecture.

The ClampZero IC is an active clamping circuit which recycles

otherwise wasted leakage inductance energy. The ClampZero

incorporates a high-side power switch and level shifted self-biased

controller which receives communication from a low-side transceiver

connected to the InnoSwitch4 primary controller

By ensuring zero voltage switching across all line and load conditions

and in both CCM and DCM operating modes, ClampZero combines with

InnoSwitch4 to implement a highly flexible active clamp flyback

solution. In a typical application paired with the InnoSwitch4 IC, the

low switching losses permit use of a high switching frequency,

minimizing the physical size of the transformer and resulting in an

extremely small PCB footprint.

Zero-voltage switching is achieved by precise timing between the

turn-off of the ClampZero and turn-on of the InnoSwitch4 power

switch, which completely removes turn-on losses. The overall effect of

this synchronized switching, along with the InnoSwitch4 PowiGaN

switch with zero turn-off losses, is a flyback converter with zero

primary clamp losses and zero power switch switching losses enabling

high density, heat sinkless flyback designs up to 220 W.