The LTC2983 is a high performance digital temperature measurement IC which directly digitises RTDs, thermocouples, thermistors and external diodes with 0.1°C accuracy and 0.001°C resolution. It 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 linearise the results.
This device can also measure temperature with standard 2-, 3-, or 4-wire RTDs, thermistors, and diodes. It has 20 reconfigurable analogue inputs enabling many sensor connections and configuration options and includes excitation current sources and fault detection circuitry appropriate for each type of temperature sensor.
In addition this device 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 digitised with three high accuracy, 24-bit ?S ADC’s, driven by an internal 10ppm/°C (maximum) reference.
The LTC2983 from Linear Technology 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. A high performance analogue front end combines low noise and low offset buffered ADCs with all the necessary excitation and control circuits for each sensor. Measurements are performed under the control of a digital engine combining all the algorithms and linearisation required for each.
This digital temperature measurement IC provides a multiplexed high precision interface to virtually any sensor. It precisely measures absolute microvolt level signals from thermocouples and ratiometric resistance measurements from RTDs and thermistors, linearises the results and outputs the results in °C or °F. Up to twenty analogue inputs are available and digitised measurements can be output in Centigrade or Fahrenheit. The SPI interface works with virtually any digital system and a comprehensive software support system with drop-down menus allows easy customising of this device.
The simple, yet feature-rich, LTC2983 interfaces with a wide variety of temperature sensors, including type B, E, J, K, N, S, R, T thermocouples, 2-, 3-, or 4-wire RTDs, 2.25k? to 30k? thermistors and temperature sensing diodes. It works with ground referenced sensors without the need for amplifiers, negative supplies, or level shift circuitry. Signals are simultaneously digitised with three, high accuracy, 24-bit ?? ADCs using an internal 10ppm/°C reference. Automatic thermocouple cold junction compensation can be done using any type of external sensor.
Included on the chip are linearisation algorithms for all common sensor types. Custom sensors can be linearised with custom coefficients programmed into the chip. Dual programmable excitation current sources feature current reversal and current ranging to improve accuracy and reduce noise. To ensure resistive measurements are accurate, current reversal eliminates thermocouple effects in the resistive sensor. Sensor specific fault detection alerts the user of short circuits, open circuits, over temperature, under temperature, and ADC over-ranging.
Demonstration software with configuration checker and C-code generation tool has been designed to help configure, programme and run the LTC2983:- Click here
The LTC2983 is offered in commercial and industrial versions, supporting operating temperature ranges from 0°C to 70°C and –40°C to 85°C respectively. The device is available in a RoHS compliant, 7mm x 7mm LQFP-48 package and all versions are available from stock. Pricing starts at $19.49 each in 1,000 piece quantities.
The USA list pricing shown is for budgetary use only. International prices may differ due to local duties, taxes, fees and exchange rates.
For more information, visit www.linear.com/product/LTC2983.
Summary of Features of the LTC2983:
- Directly Digitise RTDs, Thermocouples, Thermistors & Diodes
- Single 2.85V to 5.25V Supply
- Results Reported in °C or °F
- 20 Flexible Inputs Allow Multiple Sensor Types
- Automatic Thermocouple Cold Junction Compensation
- Built-in Standard & User-Programmable Coefficients for Linearising Thermocouples, RTDs & Thermistors
- Configurable 2-, 3-, 4-Wire RTD Configurations
- Measures Negative Thermocouple Voltages without a Negative Supply
- Automatic Burn Out, Short-Circuit & Fault Detection
- Buffered Inputs Allow External Protection & Direct Interface to Resistive Sensors
- Simultaneous 50Hz/60Hz Rejection
- Includes 10ppm/°C (Max) Reference (I-Grade)
- 48-Lead 7mm x 7mm LQFP Package
- Demo software with configuration checker and C-code generation tool
Typical Application
Applications
- Direct Thermocouple Measurements
- Direct RTD Measurements
- Direct Thermistor Measurements
- Custom Sensor Applications
Linear Technology (UK) Limited
Tel: +44 (0)1628 477066
E-mail: uksales@linear.com
Web site: www.linear.com
Website for product information: http://www.linear.com/product/LTC2983
