1 Features

• Full-load switching frequency: 50kHz to 750kHz

• IPPC control enables wide input or wide output

LLC (WLLC) operation

• Enhanced light load management:

– High frequency pulse skip for improved light

load efficiency

– Audible frequency range skip for reduced

audible noise & soft on/off burst mode

– Low frequency burst for low standby power and

integrated PFC on/off control

• Internal resonant-capacitor voltage synthesizer

for enhanced signal reliability and high start-up

frequency support

• Zero current switching (ZCS) avoidance to

eliminate capacitive region operation

• Adaptive soft start with minimized inrush current

and eliminating reverse recovery at start-up

• Integrated high-voltage start-up

• Integrated gate drive: +0.6/-1.2A

• Complete protections

– 50ns overcurrent protection (OCP), cycle-bycycle

current limit

– Overvoltage protection (OVP), output-voltage

latch

– Internal and external overtemperature

protection (OTP)

– Input and VCCP UVLO with internal 19V VCCP

Clamp

– Independently configured OCP and overload

protection

• SOIC-14 package with removed pins for highvoltage

clearance

2 Applications

• SMPS power supply for TV

• Industrial AC/DC adapters

• Power tools

• Medical power supply

• Multifunctional printer

• Enterprise and cinema projector

• PC power supply

• Gaming console power supply

• Lighting

3 Description

The UCC25661 is a high-frequency LLC controller

implementing input-power proportional control (IPPC)

scheme, along with enhanced light-load management

and multiple protection features.

IPPC widens the control range of the LLC converter

and simplifies the design of wide input or outputvoltage

range applications such as LED drivers,

battery chargers. IPPC even work without a PFC for

non-universal input applications.

The UCC25661 has enhanced light-load management

that improves the efficiency while minimizing audible

noise. To minimize standby power, the UCC25661

directly disables the PFC controller when operating in

burst mode.

The automatic capacitive region avoidance scheme

along with the adaptive soft start with reverse

recovery avoidance scheme verifies that the device

can never work in a mode where there is a potential

to damage the FETs. The automatic capacitive region

avoidance scheme makes the controller appropriate

for working with a prebiased load.

The UCC25661 comes with robust protection to help

you design a reliable power supply. The UCC25661

has options supporting high-voltage start-up, and

OVP response. See details in Device Comparison

table.