UC3853A中文资料CURRENT MODE PWM CONTROLLER FOR FORWARD AND FLYBACK APPLICATIONS数据手册UTC规格书

描述 Description

The UTC UC3853A is a high performance current mode PWMcontroller ideally suited for low standby power. Low V DD startupcurrent make the power reliable on startup design and a largevalue resistor could be used to minimize the standby power. At noload condition, the IC operates in power-saving mode for lowerstandby power, decreasing frequency for Higher conversionefficiency at light load condition. It contains protection withautomatic recovery including OLP, OCP, VCC OVP, BNO andOTP. To protect the power MOSFET, Gate-drive output is fixed upto 15V max.Excellent EMI performance is achieved with UTC proprietaryfrequency hopping technique (ZL201020615247.1) together withsoft driver control. The controller offers everything needed to buildcost−effective and reliable ac−dc switching supplies dedicated toATX power supplies. Finally a SOP-8 package saves PCB spaceand represents a solution of choice in cost sensitive project.

特性 Features

Peak Current Mode Control Adjustable Switching Frequency Adjustable Soft−start Timer Adjustable Internal Ramp Compensation Jittering Frequency ±6% of the Switching Frequency Power-saving mode for high standby efficiency Auto−recovery Primary OCP with 10ms Fixed Delay Auto−recovery Brown−Out Detection Delayed Operation Upon Start−up via an Internal Fixed Timer UC384X−like UVLO Thresholds V CC from 9V to 28V with Auto−recovery UVLO Internal 350ns Leading Edge Blanking Gate output voltage clamped at 15V UC3853A: Maximum 47% Duty Cycle UC3853B: Maximum 75% Duty Cycle