XTR116U. (TEXAS INSTRUMENTS)

The XTR116U 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 precision on-chip VREF (4.096V) can be used for offsetting or to excite transducers. A current return pin (IRET) senses any current used in external circuitry to assure an accurate control of the output current. The XTR116 is specified for operation over the extended industrial temperature range, -40 to +85°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.