DS18B20 / DS1822 温度探头电缆

DS18B20/ DS1822是常用的数字温度传感器. 它的输出是数字信号, 具有体积小等特点, 硬件开销低, 抗干扰能力强、精度高. The DS18B20 digital temperature sensor is easy to wire and can be used in a variety of situations after being packaged, 例如管道类型, 螺纹型, 磁铁吸附式, and stainless steel packaging type. 有各种型号, 包括 LTM8877, LTM8874等. As a digital temperature sensor, the DS18B20 does not require any external components when measuring temperature. It can directly output the measured temperature value of 9~12 bits (including sign bit). The temperature measurement range is -55~+125℃. The measurement accuracy is ±0.5℃ in the range of -10~+85℃, and the output measurement resolution is adjustable, up to 0.0625℃. Supporting "single-wire bus" 技术, only one general-purpose I/O port is required to complete communication with the microcontroller. The on-site temperature is directly transmitted digitally via a "single-wire bus", which greatly improves the system's anti-interference capability.

DS18B20, DS1822 "One-line bus" digital temperature sensor Same as DS1820. DS18B20 also supports "专线巴士" 界面, and the measurement temperature range is -55°C~+125°C, and the accuracy is ±0.5°C in the range of -10~+85°C. The accuracy of the DS1822 is ±2°C. The on-site temperature is directly transmitted digitally via the "专线巴士", which greatly improves the system's anti-interference capability. Suitable for on-site temperature measurement in harsh environments, such as environmental control, equipment or process control, temperature measurement consumer electronics, ETC. The new product supports a voltage range of 3V~5.5V, making system design more flexible and convenient. And the new generation of products is cheaper and smaller. Features of DS18B20 and DS1822 DS18B20 can be programmed with a resolution of 9~12 bits and an accuracy of ±0.5°C. Optional smaller package, wider voltage range. The resolution setting and the user-set alarm temperature are stored in EEPROM and are still saved after power off. The performance of DS18B20 is the best among the new generation products! The price-performance ratio is also excellent! The DS1822 is software compatible with the DS18B20 and is a simplified version of the DS18B20. The EEPROM that stores user-defined alarm temperature and resolution parameters is omitted, and the accuracy is reduced to ±2°C. It is suitable for applications with low performance requirements and strict cost control. It is an economical product. Following the early products of the "One Line Bus", the DS1820 opens up a new concept in temperature sensor technology. DS18B20 and DS1822 provide more choices in voltage, characteristics and packaging, allowing us to build an economical temperature measurement system that suits us.

Internal structure of ds18b20 temperature probe
The internal structure of DS18B20 mainly consists of four parts:
64-位光刻ROM, 温度传感器, non-volatile temperature alarm trigger TH and TL, configuration register.
The pin arrangement of DS18B20 is as follows
DQ为数字信号输入/输出端; GND是电源地; VDD为外部电源输入端 (寄生电源接线方式接地).
The 64-bit serial number in the photo etched ROM is photo etched before leaving the factory. 可以看作是DS18B20的地址序列码. 64位光刻ROM的排列是: 第一个 8 位 (28H) 是产品型号, the next 48 位是DS18B20本身的序列号, and the last 8 bits are the previous 56-bit cyclic redundancy check code (CRC=X8 +X5+X4+1). The purpose of the photolithography ROM is to make each DS18B20 different, 这样多个 DS18B20 就可以连接到一条总线上.
DS18B20中的温度传感器可以完成温度的测量. 以12位转换为例: it is provided in the form of a 16-bit sign-extended two's complement reading, 以0.0625°C/LSB的形式表示, 其中 S 是符号位.
这是12位转换后得到的12位数据, 存储在两个18B20的8位RAM中. 第一个 5 bits in binary are sign bits if the measured temperature is greater than 0. These 5 位是 0. 只需将测量值乘以 0.0625 获取实际温度. 如果温度低于 0, 这些 5 位是 1, 并且需要将测量值取反, 加 1, 然后乘以 0.0625 获取实际温度.
例如, +125℃数字输出为07D0H, +25.0625℃数字输出为0191H, -25.0625℃数字输出为FE6FH, -55℃数字输出为FC90H.