June 30, 2015 – Linear Technology Korea (CEO Hong Sa-kwak) announced the launch of a high-performance digital temperature sensor IC (Product Name: LTC2984). This product directly digitizes RTDs, thermocouples, thermistors, and extended diodes using 0.1°C conformity and 0.001°C resolution. As the successor to Linear Technology's LTC2983, the LTC2984 features an added EEPROM (electrically erasable programmable read-only memory) that stores user-configured data and custom sensor counts. This added feature eliminates the need for ICs or sensors to be programmed via a host processor, enabling the use of independent temperature sensing boards or modules. The LTC2984 is pin and software compatible with the LTC2983. In the LTC2984, non-volatile memory enhances design simplicity and reliability for modular and custom sensor systems.

The LTC2984 includes all the features of the LTC2983, plus an additional EEPROM. The high-performance analog front-end integrates a low-noise, low-offset buffered ADC and all the necessary excitation and control circuits for each sensor. The LTC2984 provides multiple high-performance interfaces to virtually any sensor. It precisely measures microvolt-level absolute signals from thermocouples and ratioscale resistance from RTDs and thermistors, linearizes the results, and outputs the values in °C or °F. Up to 20 analog inputs are supported, and digitized measurements can be output in °C or °F. The SPI interface works with virtually all digital systems, and the LTC2984 can be easily customized because its comprehensive software support system features a drop-down menu.

The simple yet feature-rich LTC2984 interfaces with a wide range of temperature sensors, including B, E, J, K, N, S, R, and T thermocouples, 2-, 3-, and 4-wire RTDs, 2.25kΩ to 30kΩ thermistors, and temperature sensing diodes. The LTC2984 operates with ground-reference sensors without amplifiers, negative power supplies, or level-shift circuits. Signals are digitized simultaneously using three high-precision 24-bit Δ∑ ADCs with an internal 15ppm/°C reference. Automatic thermocouple cold junction compensation can be implemented using various types of external sensors. Linear algorithms for all common sensor types are included on-chip. Custom sensors can be linearized using custom coefficients programmed and stored on the chip. Dual programmable excitation current sources provide current switching and current range features to improve precision and reduce noise. To ensure the accuracy of resistance measurements, current switching eliminates the thermocouple effect in resistance sensors. Sensor specific error detection notifies the user of short circuit, open circuit, overheating, below operating temperature, and ADC overranging.

The LTC2984 is available in commercial and industrial versions and supports operation over temperature ranges of 0°C to 70°C and –40°C to 85°C, respectively. The LTC2984 is available in a RoHS-compliant 7mm x 7mm LQFP 48-plate package. The price is $21.43 per unit in 1,000-unit quantities. For more information, please refer to www.linear.com/product/LTC2984.

Integrated 20-Channel Digital Temperature Measurement SoC

Product Features: LTC2984

Direct digitization possible with RTDs, thermocouples, thermistors, and diodes

- On-chip EEPROM storing channel configuration data & custom coefficients

- Single 2.85V ~ 5.25V power supply

- Flexible 20 inputs enabling various types of sensors

- Automatic thermocouple cold bonding correction

- Standard & user-programmable coefficients for linearizing thermocouples, RTDs, and thermistors

-Configurable 2-, 3-, 4-Wire RTD Configurations

- Configurable 2-, 3-, 4-wire RTD configuration environment

- Negative thermocouple voltage measurement without negative power supply

- Automatic burnout, short circuit & error detection

- External protection and direct interface for resistance sensors possible via buffer input

-50Hz/60Hz simultaneous rejection

-15ppm/°C (Max) Reference included

- 48-pin 7mm x 7mm LQFP package