The LT3798EMSE#TRPBF is a sophisticated isolated flyback controller IC designed to deliver high-performance power conversion with integrated active power factor correction (PFC). Engineered by Analog Devices, this controller is a cornerstone for applications requiring high efficiency, low total harmonic distortion (THD), and strict compliance with international power quality standards. Its primary function is to regulate power in isolated switch-mode power supplies (SMPS) while actively shaping the input current waveform to be in phase with the input voltage, thereby achieving a near-unity power factor.

This controller operates in critical conduction mode (also known as boundary conduction mode), which offers an optimal balance between switching losses and EMI performance. A key advantage of the LT3798 is its ability to drive a MOSFET directly and control a secondary-side synchronous rectifier MOSFET via an isolated driver, significantly enhancing overall efficiency by minimizing the losses typically associated with a flyback converter's output rectifier. The IC incorporates a robust internal startup regulator, allowing it to be powered directly from a high-voltage input, simplifying the external bias supply design.

Furthermore, the LT3798 features comprehensive protection circuitry, including output overvoltage protection (OVP), open-loop fault detection, and thermal shutdown, ensuring system reliability under fault conditions. Its high level of integration reduces the external component count, making it an ideal solution for compact, high-density power supplies used in industrial equipment, LED lighting systems, and consumer electronics.

ICGOODFIND

**Keywords:**

1. Isolated Flyback Controller

2. Active Power Factor Correction (PFC)

3. Critical Conduction Mode

4. Synchronous Rectification

5. High-Voltage Startup