XTR106PG4 [Texas Instruments]

The XTR106 is a low cost, monolithic 4-20mA, two-wire current transmitter designed for bridge sensors. It provides complete bridge excitation (2.5V or 5V reference), instrumentation amplifier, sensor linearization, and current output circuitry. Current for powering additional external input circuitry is available from the V_REG pin. The instrumentation amplifier can be used over a wide range of gain, accommodating a variety of input signal types and sensors. Total unadjusted error of the complete current transmitter, including the linearized bridge, is low enough to permit use without adjustment in many applications. The XTR106 operates on loop power supply voltages down to 7.5V. Linearization circuitry provides second-order correction to the transfer function by controlling bridge excitation voltage. It provides up to a 20:1 improvement in nonlinearity, even with low cost transducers.