TOP252EG

TOP252EG is a high performance off-line switcher integrated circuit with high efficiency, low component count and low component cost. It is intended for universal non-isolated power supply designs in both fixed and adjustable output voltage applications. TOP252EG is part of a family of off-line switchers from Power Integrations designed to minimize component cost while maximizing performance and reliability.

The TOP252EG integrates an N-channel MOSFET power switch and an advanced peak current-mode PWM controller in a 4mm by 5mm package. It provides protection features such as thermal shutdown, output overvoltage protection, and adjustable constant frequency current-mode control. The TOP252EG can be used in both self-oscillating flyback and quasi-resonant flyback configurations. The TOP252EG is suitable for a wide range of AC/DC power supplies, such as chargers, adapters, and POE (Power Over Ethernet).

The working principle of TOP252EG is quite simple and straightforward; it works by converting the AC mains power into DC power by rectifying it, which means that the voltage pulses obtained by rectification are full-wave and the current pulses obtained are half-wave. Once the voltage and current are in DC form, they can be converted to the required output voltage by a switching regulator circuit, called a flyback converter. The flyback converter works by repeatedly switching on and off an N-channel MOSFET, which is integrated in the TOP252EG, at a specific frequency, in order to store energy in the form of an inductive flyback, and unwind and discharge it at the required output voltage. This ensures a smooth output voltage with minimal ripples and noise, as well as efficient power conversion.

The TOP252EG, being part of a family of off-line switchers from Power Integrations, has a very low component count and cost, making it ideal for use in universal non-isolated power supplies. It provides protection features such as thermal shutdown, output overvoltage protection and adjustable constant frequency current-mode control, and is suitable for a wide range of AC/DC power supplies such as chargers and adapters. In addition, it has a very simple and straightforward working principle, making it easy to use and maintain.