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.