USR3651S

UNISONIC TECHNOLOGIES CO., LTD USR3651S HIGH PRECISION CC/CV PRIMARY-SIDE PWM POWER SWITCH CMOS IC  DESCRIPTION The UTC USR3651S 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 USR3651S 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 USR3651S 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. DIP-8 SOP-8  FEATURES * High Voltage startup circuit * 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 s...