HIGH PRECISION CC/CV PRIMARY-SIDE PWM POWER SWITCH
DESCRIPTION
The UTC UCSR3654S 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 UCSR3654S 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 UCSR3654S 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, VDD over voltage protection, VDD
clamp, OTP, leading edge blanking, VDD under voltage lockout, etc.
FEATURES
* High Voltage startup circuit
* Built-in 600V 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
* VDD under-voltage lockout |