UC3863A中文资料LOW COST POWER-SAVING MODE PWM CONTROLLER FOR FLYBACK CONVERTERS数据手册UTC规格书

描述 Description

The UC3863A is a high performance current mode PWMcontroller ideally suited for low standby power. The PWM switchingfrequency is programmable externally at normal operation. LowVDD startup current make the power reliable on startup design anda large value resistor could be used in the startup circuit tominimize the standby power. At no load condition, the IC operatesin power-saving mode for lower standby power, decreasingfrequency for Higher conversion efficiency at light load condition.The UTC UC3863A contains protection with automatic recoveryincluding OLP (over load protection), OCP (cycle-by-cycle currentlimiting), and UVLO (VDD over voltage clamp and under voltagelockout). It also provides the protections including OTP (overtemperature protection), OVP (over voltage protection) withautomatic recovery. To protect the power MOSFET, Gate-driveoutput is fixed up to 16V max.The internal slope compensation improves system stability athigh PWM duty cycle output. Leading-edge blanking on currentsense input removes the signal glitch, which offering minimalexternal component count in the design. Excellent EMIperformance is achieved with UTC proprietary frequency hoppingtechnique (ZL201020615247.1) together with soft driver control.Audio noise is eliminated due to switch frequency more than 20kHzduring operation.The UC3863A has such applications as: battery charger, poweradaptor, set-top box power supplies, ink jet printers, open-frameSMPS.

特性 Features

UTC proprietary frequency hopping technology for Improved EMI performance. Power-saving mode for high light-load and standby efficiency Dynamic peak current limiting for constant output power Built-in synchronized slope compensation OLP with automatic recovery OTP and OVP with automatic recovery VDD clamp for higher security Programmable PWM Frequency Gate output voltage clamped at 16V Low start-up current Cycle-by-cycle Current Limiting Under voltage lockout (UVLO) Few external components required