MC33368屬于集成電路（IC）的PFC（功率因數(shù)校正）。由安森美半導(dǎo)體公司制造生產(chǎn)的MC33368PFC（功率因數(shù)校正）功率因數(shù)校正 (PFC) 是用于調(diào)整交流電路中的電壓和電流之間的相位角，使之趨近于零的半導(dǎo)體器件。不同模式包括平均電流、邊界導(dǎo)通、連續(xù)導(dǎo)通、臨界導(dǎo)通、電流控制式頻率折返、不連續(xù)和不連續(xù)導(dǎo)通，開(kāi)關(guān)頻率從 6 kHz 至 1.7 MHz 可調(diào)。

The MC33368 is an active power factor controller that functions as a boost preconverter in off?line power supply applications. MC33368 is optimized for low power, high density power supplies requiring a minimum board area, reduced component count and low power dissipation. The narrow body SOIC package provides a small footprint. Integration of the high voltage startup saves approximately 0.7 W of power compared to resistor bootstrapped circuits.

The MC33368 features a watchdog timer to initiate output switching, a one quadrant multiplier to force the line current to follow the instantaneous line voltage a zero current detector to ensure critical conduction operation, a transconductance error amplifier, a current sensing comparator, a 5.0 V reference, an undervoltage lockout (UVLO) circuit which monitors the VCC supply voltage and a CMOS driver for driving MOSFETs. The MC33368 also includes a programmable output switching frequency clamp. Protection features include an output overvoltage comparator to minimize overshoot, a restart delay timer and cycle?by?cycle current limiting.

特性 Features

? Lossless Off?Line Startup

? Output Overvoltage Comparator

? Leading Edge Blanking (LEB) for Noise Immunity

? Watchdog Timer to Initiate Switching

? Restart Delay Timer

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