Isolated High Accuracy Digital Temperature Measurement System with EEPROM

The LTM2985 measures a wide variety of temperature sensors and digitally outputs the result, in °C or °F, with 0.1°C accuracy and 0.001°C resolution. The LTM2985 can measure the temperature of virtually all standard (Type B, E, J, K, N, S, R, T) or custom thermocouples, automatically compensate for cold junction temperatures and linearize the results. The device can also measure temperature with standard 2-, 3- or 4-wire RTDs, thermistors and diodes. The LTM2985 includes excitation current sources and fault detection circuitry appropriate for each type of temperature sensor.

The LTM2985 is an isolated 10-channel temperature mea-surement system software compatible with the LTC2986-1. It provides 5kV isolated power and SPI interface to the precision temperature-to-bits converter. The LTM2985 also includes a user-programmable EEPROM for custom sensor data.

APPLICATIONS

* Direct Thermocouple Measurements

* Direct RTD Measurements

* Direct Thermistor Measurements

* Custom Sensor Applications

* 5000VRMS Isolated Power and SPI Interface* Directly Digitizes 2-, 3- or 4-Wire RTDs, Thermocouples, Thermistors and Diodes* 10 Flexible Inputs Allow Interchanging Sensors* Automatic Thermocouple Cold Junction Compensation* Built-In Standard and User-Programmable Coefficients for Thermocouples, RTDs and Thermistors