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 and XTR114 are monolithic 4‑20 mA, two‑wire current transmitters that provide complete current excitation for high‑impedance RTD temperature sensors and bridge circuits. They include precision current sources, low‑error linearization, and a wide supply range, making them suitable for industrial process control, factory automation, and SCADA systems.
The document provides full specifications, typical performance curves, functional block diagrams, and application notes such as resistor selection, gain‑setting calculations, and external transistor usage. It also lists absolute maximum ratings and ordering information for the SO‑14 surface‑mount package.
| Output Current Range | 4 mA – 20 mA |
|---|---|
| Supply Voltage Range | 7.5 V to 36 V |
| Current Source (XTR112) | Two 250 µA sources |
| Current Source (XTR114) | Two 100 µA sources |
| Zero‑Output Initial Error (XTR112) | ±5 µA |
| Operating Temperature Range | –40 °C to +85 °C |
The devices operate from a supply voltage of 7.5 V up to 36 V.
The XTR112 includes two 250 µA current sources, while the XTR114 includes two 100 µA current sources for RTD excitation.
The output current follows I_O = 4 mA + VIN · (40 / RG), where VIN is the differential input voltage and RG is the gain‑setting resistor.
The internal linearization circuitry typically provides a 40:1 improvement in linearity for RTD measurements.