HIGH PRECISION CC/CV PRIMARY SIDE SWITCHING REGULATOR
DESCRIPTION
The UTC UC1103 is a primary control unit for 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 UC1103 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 UC1103 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
* ±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
* Driver MOSFET switch
* Built-in leading edge blanking
* Built-in primary winding inductance compensation
* Gate output maximum voltage clamped at 15V
* Cycle-by-cycle current limiting
* Over voltage protection
* VDD under-voltage lockout |
