XTR117AIDGKT (TEXAS INSTRUMENTS)

The XTR117AIDGKT is a Current Loop Transmitter designed to transmit analogue 4 to 20mA signals over an industry standard current loop. It provides accurate current scaling and output current limit functions. The on-chip voltage regulator (5V) can be used to power external circuitry. A current return pin (IRET) senses any current used in external circuitry to assure an accurate control of the output current. The XTR117 is a fundamental building block of smart sensors using 4 to 20mA current transmission. It is specified for operation over the extended industrial temperature range, -40 to +120°C. The external transistor, Q1, conducts the majority of the full-scale output current. Power dissipation in this transistor can approach 0.8W with high loop voltage (40V) and 20mA output current.