Dallas, Texas Texas Instruments released a voltage-to-current converter/transmitter designed for standard 0-20 mA and 4-20 mA analog signals, as well as 5-25 mA signals and voltage outputs. The XTR111 can deliver current up to 36 mA and includes output error detection and output disable. This device, from the company's Burr-Brown product line, features low supply current of 500 µA, low drift span of 5 ppm/°C and a 7 V to 44 V supply range. The XTR111 is adaptable to applications including analog current output for industrial process control and three-wire sensor systems.
The XTR111 features an external resistor that sets the ratio between the input voltage and output current. The circuit can be modified for voltage output as well. With accuracy of 0.015 percent, it is suited for current-mode sensor excitation and as a voltage-controlled current source. When combined with an external MOSFET, the XTR111 ensures large voltage compliance extending below ground as well as easy power dissipation. Output disable control can be used for conditions where the output should present zero current. The XTR111 can pre-condition sensor signals through digitally calibrated sensor signal conditioning chips, low-power microcontrollers, and combinations of instrumentation amplifiers and voltage references, or low-power op-amps and voltage references.
Pricing: $1.45 each in 1,000-piece quantities
Data Sheet: http://focus.ti.com/lit/ds/symlink/xtr111.pdf
Texas Instruments, 972-644-5580, www.ti.com