Provides temperature sensor digitization function with 0.1°C precision

November 25, 2014 – Linear Technology Korea (CEO Hong Sa-kwak, www.linear.com ) announced the release of a high-performance digital temperature measurement IC (Product Name: LTC2983). This product directly converts RTDs, thermocouples, thermistors, and external diodes into digital signals with 0.1°C precision and 0.001°C resolution. The high-performance analog front-end integrates a low-noise, low-offset buffered ADC with the essential excitation and control circuitry required for each sensor. Measurements are executed under the control of a digital engine that incorporates all algorithms and linearization required for each sensor. The LTC2983 provides multiplexed, high-precision interfaces to virtually any sensor.

This product measures absolute signals at the microvolt level from thermocouples and provides ratioometric resistance measurements from RTDs (Resistance Temperature Detectors) and thermistors, linearizing the results to display them in °C or °F. Up to 20 analog inputs are available, and digitized measurements can be displayed in Celsius or Fahrenheit. The SPI interface operates virtually with digital systems, and a comprehensive software support system with drop-down menus enables easy customization of the LTC2983.

The simple yet feature-rich LTC2983 interfaces with various temperature sensors, including B, E, J, K, N, S, R, and T type thermocouples, 2, 3, or 4-wire RTDs, 2.25kΩ to 30kΩ thermistors, and temperature sensing diodes. The LTC2983 operates with ground-referenced sensors without amplifiers, negative supplies, or level conversion circuits. Signals are digitized simultaneously using three high-precision 24-bit Δ∑ ADCs with a built-in 10 ppm/°C reference. Cold junction compensation for automatic thermocouples can be performed using external sensors. Linearization algorithms for all common sensor types are included on the chip. Custom sensors can be linearized using custom compensation factors programmed into the chip.

A dual-programmable excitation current source provides reverse current and current range features to improve precision and reduce noise. To ensure precision in resistance measurements, the reverse current eliminates thermocouple effects in the resistance sensor. Error detection suitable for the sensor informs the user of short circuits, open circuits, overheating, underheating, and ADC overranging.

The LTC2983 supports operating temperature ranges of 0°C to 70°C and –40°C to 85°C in commercial and industrial versions, respectively. The LTC2983 is available in a RoHS-compliant 7mm x 7mm LQFP-48 package. It is offered at $19.49 per unit in 1,000-unit quantities. For more information, see www.linear.com/product/LTC2983 .

Photo Caption: Integrated 20-Channel Digital Temperature Measurement SoC

Product Features: LTC2983

Direct digitization of RTDs, thermocouples, thermistors, and diodes
2.85V ~ 5.25V single power supply
20 flexible inputs enabling multiple sensor types
Automatic thermocouple cold junction correction
Standard & User-Programmable Correction Factors for Linearizing Thermocouples, RTDs, and Thermistors
Configurable 2-, 3-, 4-wire RTD configuration
Negative thermocouple voltage measurement without negative power supply
Automatic Burnout, Short Circuit & Error Detection
Buffer input capable of direct interface with external protection functions and resistance sensors
50Hz/60Hz simultaneous rejection
Includes 10ppm/°C (Max) reference
48-pin 7mm x 7mm LQFP package

The USA list pricing information provided is for general budget planning purposes only, and international prices may vary depending on local customs duties, taxes, fees, exchange rates, etc.