Texas Instruments TPS60403

Description

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

Typical applications

• 4 to 20mA Field Transmitter