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.

Features

• Inverts Input Supply Voltage
• Up to 60-mA Output Current
• Only Three Small 1-µF Ceramic Capacitors Needed
• Input Voltage Range From 1.6 V to 5.5 V
• PowerSave-Mode for Improved Efficiency at LowOutput Currents (TPS60400)
• Device Quiescent Current Typical 65 µA
• Integrated Active Schottky-Diode for Start-up Into Load
• Small 5-Pin SOT-23 Package
• Evaluation Module Available TPS60400EVM-178

Typical applications

• GaAs Bias for RF Power Amps
• Battery-Operated Equipment
• Medical Instruments
• Sensor Supply in Portable Instruments, Bipolar Amplifier Supply

More information

• Datasheet
• IC product information