Temperature Sensor to the rapid development of high-tech direction
The three main foundations of modern information technology are information collection (ie, sensor technology), information transmission (communication technology) and information processing (computer technology). Sensors are the forefront of information technology cutting-edge products, especially Temperature Sensors are widely used in industrial and agricultural production, scientific research and life and other fields, the highest number of sensors in the first.
After entering the 21st century, the Temperature Sensor is moving towards high-precision, multi-function, bus standardization, high reliability and security, the development of virtual sensors and network sensors, the development of single-chip temperature measurement system and other high-tech direction of rapid development.
1 to improve temperature accuracy and resolution
In the mid-90s of the 20th century, the first introduction of the Temperature Sensor, using the 8-bit A / D converter, the temperature accuracy is low, the resolution can only reach 1 ℃. At present, foreign countries have introduced a variety of high-precision, high-resolution Temperature Sensor, the use of 9 to 12 A / D converter, the resolution is generally up to 0.5 ~ 0.0625 ℃. DALLAS semiconductor company developed by the United States DS1624 high-resolution Temperature Sensor, can output 13-bit binary data, the resolution up to 0.03125 ℃, temperature accuracy of ± 0.2 ℃. In order to improve the multi-channel Temperature Sensor conversion rate, and some chips using high-speed successive approximation A / D converter. To AD7817 5-channel Temperature Sensor, for example, it is the local sensor, each way the remote sensor conversion time is only 27μs, 9μs.
2 to increase the test function
The test function of the new Temperature Sensor is also increasing. For example, the DS1629 single-wire Temperature Sensor adds a real-time calendar clock (RTC) to make it more functional. DS1624 also increased the storage function, the use of internal 256 bytes of chip E2PROM memory, can store the user's short message. In addition, the Temperature Sensor is from the single channel to the multi-channel direction, which for the development and development of multi-channel temperature measurement and control system to create a good condition.
Temperature Sensors have a variety of operating modes to choose from, including a single conversion mode, continuous conversion mode, standby mode, and some also increased the low temperature limit expansion mode, the operation is very simple. For some Temperature Sensors, the host (external microprocessor or microcontroller) can also set its A / D conversion rate (typical MAX6654) with the corresponding registers, resolution and maximum conversion time (typical DS1624 ).
Intelligent temperature controller is based on the development of Temperature Sensors. Typical products are DS1620, DS1623, TCN75, LM76, MAX6625. Intelligent temperature controller for a variety of micro-controller, constitute an intelligent temperature control system; they can also work independently from the microcontroller, constitute a thermostat.
3 bus technology standardization and standardization
At present, the Temperature Sensor bus technology also achieved a standardized, standardized, the bus used mainly single-wire (-Wire) bus, I2C bus, SMBus bus and spI bus.