Current loops have become the standard for signal transmissionin the process control industry. Current loops areinsensitive to noise and are immune to errors from lineimpedance. Burr-Brown offers a complete line of monolithic4mA to 20mA current loop transmitters and receivers.General purpose two-wire 4-20mA current-loop transmitter.This transmitter has an instrumentation amplifier input andtwo 1mA current sources for transducer excitation andoffsetting.