[FAQ] What is a 2-wire 4-20mA current transmitter?

2-wire transmitters are loop powered devices most commonly used to monitor a remote process with no access to a local supply. Two analog signal wires carry both the analog output signal, and power for the sensor/monitoring circuitry and transmitter. The attached blog series will provide an overview and explain the design considerations of 2-wire systems.

2-Wire 4-20mA Sensor Transmitters: Background + Compliance Voltage

2-Wire 4-20 mA Sensor Transmitters: Understanding the 2-wire Transmitter GND

2-Wire 4-20mA Sensor Transmitters: Sensor and Transmitter Current Consumption Limitations

2-wire 4-20mA transmitters: Controlling 2-Wire Transmitter Outputs with Externally Powered Sources

2-wire 4-20mA sensor transmitters: Designing Input Isolated 2-Wire Sensor Transmitters

2-wire 4-20mA sensor transmitters: Increasing Sensor Power with Switching Power Supplies

Industrial DACs: How to design 2-wire transmitters

Industrial DACs: How to protect 2-wire transmitters

TI Devices:

Analog input, analog output: XTR101, XTR105, XTR106, XTR108, XTR112, XTR115, XTR116, XTR117

Digital input, analog output: DAC161S997, DAC161P997

You can check out the post titled: Are there reference designs that can help me build a 4-20mA transmitter? For help finding reference designs using some of the above devices.