XTR104

® XTR104 4-20mA Current Transmitter with BRIDGE EXCITATION AND LINEARIZATION FEATURES q LESS THAN ±1% TOTAL ADJUSTED ERROR, –40°C TO +85°C q BRIDGE EXCITATION AND LINEARIZATION q WIDE SUPPLY RANGE: 9V to 40V q LOW SPAN DRIFT: 50ppm/°C max q HIGH PSR: 110dB min q HIGH CMR: 80dB min BRIDGE NONLINEARITY CORRECTION USING XTR104 2.0 Uncorrected Bridge Output 1.5 Nonlinearity (%) APPLICATIONS q INDUSTRIAL PROCESS CONTROL q FACTORY AUTOMATION q SCADA q WEIGHTING SYSTEMS q ACCELEROMETERS DESCRIPTION The XTR104 is a monolithic 4-20mA, two-wire current transmitter integrated circuit designed for bridge input signals. It provides complete bridge excitation, instrumentation amplifier, linearization, and current output circuitry necessary for high impedance strain gage sensors. The instrumentation amplifier can be used over a wide range of gain, accommodating a variety of input signals and sensors. Total adjusted error of the complete current transmitter, including the linearized bridge is less than ±1% over the full –40°C to +85°C temperature range. This includes zero drift, span drift and non-linearity for bridge outputs as low as 10mV. The XTR104 operates on loop power supply voltages down to 9V. Linearization circuitry consists of a second, fully independent instrumentation amplifier that controls the bridge excitation voltage. It provides second-order correction to the transfer function, typically achieving a 20:1 improvement in nonlinearity, even with low cost transducers. The X...