US4651S

UNISONIC TECHNOLOGIES CO., LTD US4651S LINEAR INTEGRATED CIRCUIT LOW COST POWER-SAVING MODE POWER-SWITCH FOR FLYBACK CONVERTERS  DESCRIPTION The UTC US4651S is a high performance current mode power-switch ideally suited for low standby power. Drain start up make the power reliable on startup design and lower standby power. At no load condition, the IC operates in power-saving mode for lower standby power, decreasing frequency for Higher conversion efficiency at light load condition. The UTC US4651S contains protection with automatic recovery including OLP (over load protection), OTP (over temperature protection), OVP (over voltage protection), UVLO (VDD over voltage SOP-8 clamp and under voltage lockout).To protect the power MOSFET, Gate-drive output is fixed up to 16V max. The UTC US4651S contains protection OCP (cycle-by-cycle current limiting). The internal slope compensation improves system stability at high PWM duty cycle output. Leading-edge blanking on current sense input removes the signal glitch, which offering minimal external component count in the design. Excellent EMI performance is achieved with UTC proprietary frequency hopping technique (ZL201020615247.1) together with soft driver control. Audio noise is eliminated due to switch frequency more than 20kHz during operation. The UTC US4651S has such applications as: battery charger, power adaptor, set-top box power supplies, ink jet printers, open-frame SMPS.  FEATURES * UTC proprietary frequency hoppi...