UCC38050

转换模式 PFC 控制器

The and UCC38051 are PFC controllers for low-to-medium power applications requiring compliance with IEC 1000-3-2 harmonic reduction standard. The controllers are designed for a boost preregulator operating in transition mode also referred to as boundary-conduction mode or critical conduction-mode operation. They feature a transconductance voltage amplifier for feedback error processing, a simple multiplier for generating a current command proportional to the input voltage, a current-sense PWM comparator, PWM logic, and a totem-pole driver for driving an external FET.

In the transition mode operation, the PWM circuit is self-oscillating, with the turnon being governed by an inductor zero-current detector ZCD pin, and the turnoff being governed by the current-sense comparator. Additionally, the controller provides features such as peak current limit, default timer, overvoltage protection OVP and enable.

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Transition Mode PFC Controller for Low Implementation Cost

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Industry Pin Compatibility With Improved Feature Set

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Improved Transient Response With Slew-Rate Comparator

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Zero Power Detect to Prevent Overvoltage Protection OVP During Light Load Conditions

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Accurate Internal VREF for Tight Output Regulation

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Two UVLO Options

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OVP, Open-Feedback Protection, and Enable Circuits

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±750-mA Peak Gate Drive Current

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Low Start-Up and Operating Currents

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Lead Pb-Free Packages