GENERAL DESCRIPTION

The ADT70 provides excitation and signal conditioning for resistance-temperature devices (RTDs). It is ideally suited for 1 kΩ Platinum RTDs (PRTDs), allowing a very wide range of temperature measurement. It can also easily interface to 100 Ω PRTDs. Using a remote, low cost thin-film PRTD, the ADT70 can measure temperature in the range of –50°C to +500°C.

With high performance platinum elements, the temperature change can be extended to 1000°C. Accuracy of the ADT70 and PRTD system over a –200°C to +1000°C temperature range heavily depends on the quality of the PRTD. Typically the ADT70 will introduce an error of only ±1°C over the transducers temperature range, and the error may be trimmed to zero at a single calibration point.

FEATURES

  PRTD Temperature Measurement Range

  Typical IC Measurement Error 618C

  Includes Two Matched Current Sources

  Rail-to-Rail Output Instrumentation Amp

  Uncommitted, Rail-to-Rail Output Op Amp

  On-Board 12.5 V Reference

  Temperature Coefficient 625 ppm/8C

  15 V or 65 V Operation

  Supply Current 4 mA Max

  10 mA Max in Shutdown

APPLICATIONS

  Temperature Controllers

  Portable Instrumentation

  Temperature Acquisition Cards