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 am-
plifier, and current output circuitry on a single inte-
grated 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 trans-
mitter is low enough to permit use without adjustment
in many applications. This includes zero output cur-
rent drift, span drift and nonlinearity. The XTR112
and XTR114 operate on loop power supply voltages
down to 7.5V.