UNISONIC TECHNOLOGIES CO., LTD
USR3651
Preliminary CMOS IC
1 of 8
Copyright © 2018 Unisonic Technologies Co., Ltd
QW-R129-035.a
HIGH PRECISION CC/CV
PRIMARY-SIDE PWM POWER
SWITCH
DESCRIPTION
The UTC USR3651 is a primary control switch mode charger
and adapter applications. The controlled variable is transferred by
an auxiliary winding from the secondary to the primary side. The
device integrates PWM controller to enhance the performance of
discontinuous conduction mode (DCM) flyback converters.
The UTC USR3651 operates in primary-side sensing and
regulation. Opto-coupler and TL431 could be eliminated. It also
provides off-time modulation to linearly decrease PWM frequency
under light-load conditions so that low standby power can be
achieved.
The UTC USR3651 achieves high precision CV/CC regulation
and high power efficiency. It offers comprehensive protection
coverage with auto-recovery features including Cycle-by-cycle
current limiting, V
DD
over voltage protection, V
DD
clamp, OTP,
leading edge blanking, V
DD
under voltage lockout, etc.
FEATURES
* Built-in 650V Power MOSFET
* ±5% constant voltage regulation at universal AC input
* High precision constant current regulation at universal AC input
* Primary side control without TL431 and opto-coupler
* Programmable CV and CC regulation
* Programmable cable compensation in CV mode
* Flyback topology in DCM operation
* Frequency hopping to reduce system EMI
* Built-in leading edge blanking
* Built-in primary winding inductance
compensation
* Power on soft start
* Gate Output Maximum Voltage Clamped at
15V
* Cycle-by-cycle current limiting
* Over voltage protection
* V
DD
under-voltage lockout
ORDERING INFORMATION
Ordering Number
Lead Free Halogen Free
Package Packing
USR3651L-S08-R USR3651G-S08-R
SOP-8 Tape Reel