LFA75F-36-SJ1

AC DC converters occupy an important role in the modern electronic industry. They convert the AC voltage from the power grid to the desired DC voltage for the specific application. Furthermore, the devices design is optimized to provide protection to the system it is used in. In this context, the LFA75F-36-SJ1 AC DC converter is a highly efficient and reliable unit to meet the demands in certain applications.

Introduction

The LFA75F-36-SJ1 is a high frequency switched mode power supply (SMPS) featuring an all-in-one integrated circuit (IC) with various input/output stages. This converter offers an impressive power conversion efficiency of up to 92%, and an output power of up to 35W. With a maximum standby power of 0.2W, it meets the established EU ErP directives making it suitable for compliance with the current energy regulations. Additionally the unit is compliant with the heavy industrial EMC levels and agency safety certifications.

This converter is available in open frame, SMT, and DIN rail formats suitable for different types of applications, being the ideal choice for industrial, medical, instrumentation and telecom applications.

Application Field and Working Principle

The LFA75F-36-SJ1 is dedicated to applications where generating a consistent and regulated DC voltage is a must. The device is particularly suitable for systems where tight regulation, reliability, and good EMC performance are required. In several industries such as medical and telecommunications, the unit can be used to power instrumentation and digital signal processing equipment.

The power conversion is accomplished through a Transformer Coupled Converter (TCC) topology. This topology works similarly to a resonant converter such as the fly-back, but the magnetic components used are significantly smaller as no core resetting is performed. Additionally, the TCC topology offers better efficiency and immunity to input voltage drops.

The operation of the LFA75F-36-SJ1 is simple, and efficient. The device works as follows, an input rectifier block rectifies the AC voltage provided from the power grid to a pulsating DC voltage; this voltage is usually around 400V. This rectified voltage is then processed by an LLC resonant half bridge to obtain a high frequency AC voltage. This voltage is rectified again to obtain a high voltage DC voltage which is then processed by an output stage IC. The output stage provides the necessary output voltage for the application.

AC DC converters require protection against abnormal conditions such as input voltage drops and surges, and component failures in the system. In this regard the LFA75F-36-SJ1 is protected against short circuit, overvoltage, overload, and over temperature events; also the unit is short-circuit proof against the input voltage.

Technical Specifications

The LFA75F-36-SJ1 is part of the TDK-Lambda family of AC DC converters optimized for energy efficiency and reliability. The product offers wide input voltage range from 85 to 264 Vac, useful for industrial applications with variable input voltages. A universal input is also available in the construction. The output voltage is adjustable from 6.48 to 36VDC with a 1/20V resolution.

Conclusion

The LFA75F-36-SJ1 AC DC converter is a highly efficient solution for a wide variety of industrial applications. It efficiently manages the power conversion with its Transformer Coupled Converter topology where a high frequency AC voltage is obtained. The unit is an all-in-one integrated circuit design for smaller boards and more restricted power systems with impressive features such as high power conversion efficiency, excellent EMC immunity, and protection against abnormal load conditions.