1 Features
• Full-load switching frequency: 50kHz to 750kHz
• IPPC control enables wide input and output LLC
(WLLC) operation
• Enhanced light load management:
– High-frequency pulse skip for improved light
load efficiency
– Low-frequency burst for low standby power
– Audible frequency range skip for reduced
audible noise
– Integrated PFC on/off control signal to help
further reduce standby power (UCC256614-Q1)
• 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
• Integrated high-voltage start-up (UCC256612-Q1
and UCC256614-Q1)
• Integrated gate driver: +0.6A and –1.2A
• Complete protections
– Overcurrent protection (OCP): 50ns, cycle-bycycle
current limit
– Overvoltage protection (OVP), internal and
external overtemperature protection (OTP)
– Input and VCCP UVLO with internal 19V VCCP
Clamp
– Independently configured OCP and
overload protection (OLP) (UCC256612-Q1,
UCC256613-Q1, and UCC256614-Q1)
• SOIC-14 package with removed pins for highvoltage
clearance

2 Applications
• Cell monitor unit and battery junction box
• HEV/EV OBC and DC/DC converter
• EV charging infrastructure
• HEV/EV inverter and motor control
• Zone and body domain controller

3 Description
The UCC25661x-Q1 family is a high-frequency LLC
controller that implements a input-power proportional
control (IPPC) scheme, along with enhanced lightload
management and multiple protection features.
IPPC widens the control range of the LLC converter
and simplifies the design of wide input applications,
such as high voltage to low voltage (HV-LV)
redundant auxiliary, key-off, and bias isolated power
supplies. IPPC simplifies the design of wide output
applications, such as light electric vehicle battery
chargers (scooters, mopeds, golf carts, and fork lifts).
The UCC25661x-Q1 family has enhanced light-load
management that improves efficiency and minimizes
audible noise. To minimize standby power in charger
applications, the UCC25661x-Q1 family directly
disables the PFC controller when operating in burst
mode.
The automatic capacitive region avoidance scheme,
along with the adaptive soft start with a reverse
recovery avoidance scheme, establishes that the
device never works in a mode where there is
a potential to damage the FETs. Because of the
automatic capacitive region avoidance scheme, the
controller works best with a prebiased load.
The UCC25661x-Q1 family comes with robust
protection for designing a reliable power supply. The
UCC25661x-Q1 family has options supporting various
features, see details in the Device Comparison table.