ClampZero Family
www.power.com November 2020
Active Clamp IC with Integrated High-Voltage Switch
Pairs with InnoSwitch4 Family of Ofine Switcher ICs
This Product is Covered by Patents and/or Pending Patent Applications.
Product Highlights
Highly Integrated, Compact Footprint
• Eliminates switching losses in InnoSwitch4 primary switch
• Captures and recycles leakage inductance energy
• Dramatically improves power supply efciency
• Interfaces seamlessly with InnoSwitch4
• Powered directly from InnoSwitch4 BYPASS pin
• Self-biased at start-up
• Operates in both DCM and CCM modes
Advanced Protection / Safety Features
• Integrated temperature sensing and hysteretic thermal shutdown
Green Package
• Halogen free and RoHS compliant
Applications
• High density yback designs up to 135 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 efciency –
easily exceeding 95% - while maintaining the exibility and low
component count of the yback 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 exible active clamp yback
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 yback converter with zero
primary clamp losses and zero power switch switching losses enabling
high density, heatsinkless yback designs up to 135 W.
Figure 1. Typical Application schematic.
ClampZero + InnoSwitch4 Output Power Table
Product
3
85-265 VAC
Adapter
1
Open Frame
2
CPZ1061M 75 W 85 W
CPZ1062M 120 W 135 W
Table 1. Output Power Table.
Notes:
1. Minimum continuous power in a typical non-ventilated enclosed typical size
adapter measured at 40 °C ambient. Max output power is dependent on the
design. With condition that package temperature must be < 125 °C.
2. Minimum peak power capability.
3. Package: MinSOP-16A.
Figure 2. MinSOP-16A Package with Creepage for High-Side Driver.
PI-9086c-112320
ClampZero
High-Voltage
DC Input
S2
D
BP2
S1
BP1
IN
HS
LS
InnoSwitch4-CZ
