TCN75 intelligent Temperature Sensor serial interface
Since the 21st century, intelligent Temperature Sensor is to high-precision, multi-function, bus standardization, high reliability and security development, the development of virtual Temperature Sensors and network Temperature Sensors, the development of single-chip temperature measurement system and other high-tech direction of rapid development.
1.1 Intelligent Temperature Sensor to improve the temperature accuracy and resolution: the first launch of intelligent Temperature Sensor, the temperature accuracy is low, the resolution can only reach 1 ° C. At present, China has introduced a variety of high-precision, high-resolution intelligent Temperature Sensor, using 9? 12 A / D converter, the resolution is generally up to 0.5? 0.0625 ° C. Developed by the United States DALLAS semiconductor company new DS1624 high-resolution intelligent Temperature Sensor, can output 13 binary data, the resolution up to 0.03125 ° C, the temperature accuracy of ± 0.2 ° C
1.2 intelligent Temperature Sensor to improve multi-channel conversion speed: In order to improve the multi-channel intelligent Temperature Sensor conversion rate, some chips also use high-speed successive approximation A / D converter. To AD7817 5-channel intelligent Temperature Sensor, for example, in the local sensor, each remote sensor conversion time is only 27us, 9us. In addition, the intelligent Temperature Sensor from single channel to multi-channel direction, which is to develop and develop multi-channel temperature measurement and control system to create the conditions.
1.3 intelligent Temperature Sensor to increase the versatility: the versatility of the new intelligent Temperature Sensor is also increasing.
1, DS1629 single-line intelligent Temperature Sensor, increase the real-time calendar clock (RTC) to make its function more perfect.
2, DS1624 also increased the storage function, the use of internal 256 bytes of chip E2PROM memory, you can store the user's text messages.
3, the latest development of intelligent Temperature Sensors (such as MAX6654, LM83) also increased the sensor fault detection function, can automatically detect the external transistor Temperature Sensor (also known as remote sensor) open or short circuit fault.
4, MAX6654 can choose "parasitic impedance offset" (PArAsitic ResistAnce CAncellAtion, abbreviated as prc) can offset the temperature error caused by the remote sensor lead impedance, even if the lead impedance of 100 ohms, it will not affect the measurement accuracy.
5, TCN75 intelligent Temperature Sensor serial interface, interrupt / compare signal output and address input can withstand 1000V electrostatic discharge voltage. LM83 intelligent Temperature Sensor can withstand 4000V electrostatic discharge voltage. Intelligent Temperature Sensor with a variety of operating modes to choose from, including 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 intelligent Temperature Sensors, the host (external microprocessor or microcontroller) can also set its A / D slew rate (typically MAX6654) through the corresponding registers, resolution and maximum conversion time (typical product DS1624).
1.4 Intelligent Temperature Sensor bus technology standardization and standardization At present, the intelligent Temperature Sensor bus technology is also standardized, standardized, the main bus used is a single line (1-Wire) bus, I2C bus, SMBus bus and spI bus. The Temperature Sensor as a slave can communicate with the host via a dedicated bus interface.
Temperature Sensors are used in our ordinary life, such as indoor air conditioners, refrigerators and microwave ovens and other household appliances, and how to determine the microwave inside the food is hot enough and will not burn it? This requires the use of Temperature Sensors. At the bottom of the microwave, the heat source is equipped with a Temperature Sensor probe that recognizes the initial temperature and has multiple probes in the internal space to detect the internal temperature and communicate to the bottom probe, precisely controlling the temperature. And requires a high-performance, stable structure, can be anti-magnetic interference Temperature Sensor.
Temperature Sensor in the microwave oven is the use of thermistor changes with the characteristics of temperature changes, the power of the electromotive force E = 9.0V, the internal resistance is negligible; G for the sensitive current meter, the internal resistance Rg remain unchanged; R for the thermal Resistance, closed switch S, when the temperature of R is equal to 20 ℃, ammeter I1 = 2mA, when the ammeter reading is I2 = 3.6mA, the temperature of the thermistor R.