Features

• Directly Digitizes 2-, 3-, or 4-Wire RTDs, Thermocouples, Thermistors, and Diodes
• On-Chip EEPROM Stores Channel Configuration Data and Custom Coefficients
• Single 2.85V to 5.25V Supply
• 20 Flexible Inputs Allow Interchanging Sensors
• Automatic Thermocouple Cold Junction Compensation
• Built-In Standard and User-Programmable Coefficients for Thermocouples, RTDs and Thermistors
• Measures Negative Thermocouple Voltages
• Automatic Burn Out, Short-Circuit and Fault Detection
• Buffered Inputs Allow External Protection
• Simultaneous 50Hz/60Hz Rejection
• Includes 15ppm/°C (Max) Reference (I-Grade)
• Demo software with configuration checker and C-code generation tool

Typical Application

Description

The LTC®2984 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 LTC2984 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. It has 20 reconfigurable analog inputs enabling many sensor connections and configuration options. The LTC2984 includes excitation current sources and fault detection circuitry appropriate for each type of temperature sensor as well as an EEPROM for storing custom coefficients and channel configuration data.

The LTC2984 allows direct interfacing to ground referenced sensors without the need for level shifters, negative supply voltages, or external amplifiers. All signals are buffered and simultaneously digitized with three high accuracy, 24-bit ΔΣ ADC's, driven by an internal 10ppm/°C (maximum) reference.