The three foundations of modern information technology are information collection (i.e. sensor technology), information transmission (communication technology), and information processing (computer technology). Sensors belong to the forefront of information technology, especially temperature sensors, which are widely used in fields such as industrial and agricultural production, scientific research, and daily life, and have the highest number of sensors. In the past century, the development of temperature sensors has roughly gone through the following three stages:; (1) Traditional discrete temperature sensors (including sensitive components); (2) Simulate integrated temperature sensors/controllers; (3) Intelligent temperature sensor. At present, new types of temperature sensors are developing from analog to digital, from integration to intelligence and networking internationally.

Product classification of integrated temperature sensors

1.1 Simulated integrated temperature sensor

Integrated sensors are made using silicon semiconductor integration technology, hence also known as silicon sensors or single-chip integrated temperature sensors. The analog integrated temperature sensor was introduced in the 1980s. It is a specialized IC that integrates temperature sensors on a single chip and can perform temperature measurement and analog signal output functions. The main characteristics of analog integrated temperature sensors are single function (only measuring temperature), small temperature measurement error, low price, fast response speed, long transmission distance, small volume, micro power consumption, etc. They are suitable for long-distance temperature measurement and control without the need for nonlinear calibration, and the peripheral circuit is simple. It is currently a widely used integrated sensor both domestically and internationally, with typical products including AD590, AD592, TMP17, LM135, etc.

1.2 Simulated integrated temperature controller

Simulated integrated temperature controllers mainly include temperature control switches and programmable temperature controllers. Typical products include LM56, AD22105, and MAX6509. Some enhanced integrated temperature controllers (such as TC652/653) also include A/D converters and solidified programs, which have some similarities with intelligent temperature sensors. But it forms its own system and is not controlled by the microprocessor during operation, which is the main difference between the two.

1.3 Intelligent temperature sensors

Intelligent temperature sensors (also known as digital temperature sensors) were introduced in the mid-1990s. It is the crystallization of microelectronics technology, computer technology, and automatic testing technology (ATE). At present, various intelligent temperature sensor series products have been developed internationally. Intelligent temperature sensors all contain temperature sensors, A/D converters, signal processors, memory (or registers), and interface circuits. Some products also come with a multiplexer, central controller (CPU), random access memory (RAM), and read-only memory (ROM). The characteristic of intelligent temperature sensors is that they can output temperature data and related temperature control variables, and are compatible with various microcontrollers (MCUs); And it achieves testing functions through software on the basis of hardware, and its level of intelligence also depends on the level of software development.

New Trends in the Development of 2 Intelligent Temperature Sensors

After entering the 21st century, intelligent temperature sensors are rapidly developing towards high-tech directions such as high precision, multifunctionality, bus standardization, high reliability and security, development of virtual sensors and network sensors, and development of single-chip temperature measurement systems.