描述 Description

The UTC UC3875L is a high performance current mode PWM controller ideally suited for low standby power. The PWM switching frequency is programmable externally at normal operation. 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, decreasingfrequency for Higher conversion efficiency at light load condition. The UTC UC3875L contains protection with automatic recovery including OLP (over load protection), OCP (cycle-by-cycle current limiting), and UVLO (VDD over voltage clamp and under voltage lockout). It also provides the protections including OTP (over temperature protection), OVP (over voltage protection) in UC3875L with latch up. To protect the power MOSFET, Gate-drive output is fixed up to 16V max.?? 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 UC3875L has such applications as: battery charger, power adaptor, set-top box power supplies, ink jet printers, open-frame SMPS.

特性 Features

UTC proprietary frequency hopping technology for Improved EMI performance.?Lower than 30mW Standby Power DesignDynamic peak current limiting for constant output powerBuilt-in synchronized slope compensationOLP with automatic recoveryOTP and OVP with latch upVDD clamp for higher securityProgrammable frequencyGate output voltage clamped at 16VLow start-up currentCycle-by-cycle Current LimitingUnder voltage lockout (UVLO)Few external components required