Linear Technology Corporation launched a high-performance digital temperature measurement IC LTC2984, the device could directly digitize to the resistance temperature detector (RTD), thermocouples, thermistors and external diodes, and with the accuracy of 0.1 ° C and resolution of 0.001 ° C. Linear Technology Corporation LTC2984 is basis of the LTC2983 and increased EEPROM for storing user profile data and custom sensors coefficient (Electrically Erasable Programmable Read Only-Memory). By adding EEPROM it eliminates the requirement program by a host processor to any IC or sensor, what’s more, it’s also advantageous for facilitate use self-contained temperature detection circuit board or module. LTC2984 and LTC2983 are compatible in pin and software. Non-volatile storage in LTC2984 can simplify design and improve modular and reliability of custom sensor system.
LTC2984 owns all the features of LTC2983 and added EEPROM. A high-performance analog forepart combined the low noise and low offset buffer ADC with all necessary drive and control circuit for each type of sensor. Measurement is going under the control of integrated all algorithms required for each sensor and digital engine of linearized function circuit. LTC2984 provides a high precision multiplexed interface that can be connected with almost any sensor. The device can accurately measure the absolute microvolt level signals from thermocouples and ratio resistance from the RTD and thermistor to digitizing process the measured results and with ° C or ° F unit of output. It can provide up to 20 analog inputs, and can output digital measurements in Celsius or Fahrenheit as the unit output. SPI interface could work with virtually any digital system, and the comprehensive software supporting system with pull-down menu enables you to achieve simple custom of LTC2984.
Simple and function-rich LTC2984 can be connected to a variety of temperature sensors, including types of B, E, J, K, N, S, R and T thermocouples, two-wire, three-wire or four-wire RTD, 2.25kΩ to 30kΩ thermistor, as well as temperature-sensing diode. LTC2984 can be used with ground-referenced sensors without an amplifier, a negative power supply or the level shift circuit. By using internal 15ppm / ° C reference, signal can be digitized at the same time with three high-accuracy 24 ΔΣ ADC. Automatic thermocouple cold junction compensation could achieve by any type of external sensor. All common types of sensors of linearization algorithms are built on the chip. Customized sensors can be linearized using the custom coefficient set and stored on the chip. Dual programmable drive current sources with current reversal and current range functions to improve accuracy and reduce noise. To ensure the accuracy of resistance measurement, current reversal eliminates the thermocouple effect from resistive sensor. The specific sensor fault detection circuit can give the users warning signals like short circuit, open circuit, over-temperature, low- temperature and ADC exceeds the rated range.
LTC2984 has commercial and industrial temperature versions, which respectively support operating temperature range from 0 ° C to 70 ° C and from -40 ° C to 85 ° C. LTC2984 adopts RoHS-compliant 7mm x 7mm LQFP 48-lead package. Purchase unit price is $ 21.43 for at least 1000 approved.
Caption: complete 20-channel digital temperature measurement SoC.
Summary of Features of LTC2984:
• Direct Digital RTD, thermocouples, thermistors and diode.
• Built-in EEPROM storage channel configuration data and customization coefficient.
• Single-supply from 2.85V to 5.25V.
• 20 flexible input support multiple types of sensors.
• Automatic thermocouple cold junction compensation.
• Standard and user-programmable coefficients for the linearized thermocouple, RTD and thermistor.
• Configurable Two-wire, three-wire and four-wire RTD.
• No negative supply can be measured negative voltage thermocouple.
• Automatic detection for burning, short circuit and fault.
• Buffered input allows external protection and directly connected to the resistance sensor.
• Suppress 50Hz / 60Hz at the same time.
• Including 15ppm / ° C (max) reference.
• 48-lead package 7mm x 7mm LQFP.
