SLAAEH7 February   2024 MSPM0L1306

 

  1.   1
  2.   Abstract
  3.   Trademarks
  4. 1Introduction
    1. 1.1 System Description
    2. 1.2 Design 1: High Efficiency Design with 50kHz
    3. 1.3 Design 2: Space Optimized Design with 250kHz
    4. 1.4 Design 3: MCU Driven Design with Flexible Switching Frequency
      1. 1.4.1 Selection of MOSFETs
      2. 1.4.2 Efficiency Test
        1. 1.4.2.1 Current Consumption of PWM (Ipwm) Test
        2. 1.4.2.2 Efficiency Test Set Up
        3. 1.4.2.3 Efficiency Test Results at 50kHz Switching Frequency
        4. 1.4.2.4 Efficiency Test Results at 250kHz Switching Frequency
  5. 2Design File
    1. 2.1 Schematics
    2. 2.2 Bill of Materials
  6. 3Summary
  7. 4References

Abstract

This application note describes three designs of isolated low power supplies for 2-wire loop powered 4 to 20mA field transmitters or sensors, which are all based on primary side half-bridge topology and secondary side Schottky rectification. The design 1 is using a switching frequency of 50kHz and providing the best in class efficiency, which is available on ti.com as TIDA-00349. The design 2 focuses on optimizing the board space with operating switching frequency of 250kHz and using the customized low size transformer. Furthermore, the design 3 provides maximum of flexibility in terms of switching frequency up to 500kHz by using MSPM0 to generate two channels of PWM (Pulse Width Modulation) signals. This application note describes the design 3 in detail.