XTR114UG4 [Texas Instruments]

The XTR112 and XTR114 are monolithic 4-20mA, two-wire current transmitters. They provide complete current excitation for high impedance platinum RTD temperature sensors and bridges, instrumentation amplifier, and current output circuitry on a single integrated circuit. The XTR112 has two 250µA current sources while the XTR114 has two 100µA sources for RTD excitation. Versatile linearization circuitry provides a 2nd-order correction to the RTD, typically achieving a 40:1 improvement in linearity. Instrumentation amplifier gain can be configured for a wide range of temperature or pressure measurements. Total unadjusted error of the complete current transmitter is low enough to permit use without adjustment in many applications. This includes zero output current drift, span drift and nonlinearity. The XTR112 and XTR114 operate on loop power supply voltages down to 7.5V. Both are available in an SO-14 surface-mount package and are specified for the –40°C to +85°C industrial temperature range.