UC3837

UNISONIC TECHNOLOGIES CO., LTD UC3837 Preliminary LINEAR INTEGRATED CIRCUIT LOW COST POWER-SAVING MODE PWM CONTROLLER FOR FLYBACK CONVERTERS  DESCRIPTION The UC3837 is a high performance current mode PWM controller ideally suited for low standby power. Low VDD startup current make the power reliable on startup design and a large value resistor could be used in the startup circuit to minimize the 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 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 UC3837 has such applications as: battery charger, power adaptor, set-top box power supplies, ink jet printers, open-frame SMPS. 54 6 1 23 SOT-26  FEATURES * UTC proprietary frequency hopping technology for Improved EMI * Programming BNO for higher security performance. * Fixed switch frequency 65kHz * Power-saving mode for high light-load and standby efficiency * Gate output voltage clamped at 15V * Soft Start * Low start-up current * Dynamic peak...