集成温度传感器AD590的应用.docx

1、集成温度传感器AD590的应用集成温度传感器AD590的应用AD590测温电路及其应用 引言 集成温度传感器实质上是一种半导体集成电路，它是利用晶体管的b - e结压降的不饱和值V与热力学温度T和通过发射极电流I的关系实现对温度的检测。 集成温度传感器具有线性好、精度适中、灵敏度高、体积小、使用方便等优点，得到广泛应用。 集成温度传感器的输出形式分为电压输出和电流输出两种。电压输出型的灵敏度一般为 10 mV,K ，温度0?时输出为0，温度25?时输出2.982 V。电流输出型的灵敏度一般为 1A,K 。 ,1 AD590简介 1(1 特性 AD590是美国模拟器件公司生产的单片集成两端感温电

2、流源。 它的主要特性如下: ( 1 ) 测温范围- 55?+l50?; ,( 2 ) 线性电流输出lA, K; ( 3 ) 线性度好，满刻度范围为?0 .3?; ( 4 ) 电源电压范围4 30 V，当电源电压在5 10V之间，电压稳定度为l ,时，所产生的误差只有?0.01?; ,( 5 ) 电阻采用激光修刻工艺，使在+ 25? ( 298.2K) 时，器件输出298.2A: ( 6 ) 功率损耗低。 1.2 AD590的工作原理 AD590通过利用硅晶体管的基本性能来实现与温度成正比这一特性，二极管的基本方程为: the responsible unit fined 200 Yuan, c

3、onstruction person in charge a fine of 50 Yuan. (8) no permit to work and the job in accordance with the provisions, on the job unit fined 300 yuan, the unit will charge a fine of 100 Yuan. 7.5.3 accident penalties (1) injuries fatalities directly punished 12 million. Direct responsibility for the a

4、ccident and have the corresponding responsibility of leadership, such as concerning administrative sanctions, should be brought to the company or the relevant Department. (2) personal injury accident occurred, the direct punishment 0.5-10,000 yuan, responsible for the direct responsibility for the a

5、ccident and the responsibility of leadership, such as concerning administrative sanctions should be dealt with by the personnel Department of the company. (3) personal injury accident occurs, the direct punishment 500-1000, who is directly responsible for the accident responsibility, give notice of

6、criticism and 50-100 economic sanctions against them. (4) to conceal the accident, reported without undue delay or false, to inform the administrative leadership of the criticism, resulting in serious consequences, the pursuit of leadership, along with 500-1000 punishment. (5) significant near miss

7、should be attempted as the case of responsible for the accident and construction team injuries accident penalty provisions, mutatis mutandis. Eight, should perform in the construction standards and specifications, serial number a 1 GB3323-2005qV/KTqV/KTbcI = I s ( e-1 ) ?I s(e ( 1 ) 式中，I 通过二极管的电流 I

8、s 二极管的反向饱和电流 V二极管两端电压 (伏) bc,19q 电子电荷量，等于 1.60210 (库) ，,23K常数，等于 1.38 10 (焦耳,K ) ，T绝对温度 ( K ) qV/KTbc由式 (1 ) 可知，I,I s = e ， 所以 V = KT,q?l n I / I s = KT,q?l n J ( 2 ) bc由式 ( 2 ) 可知V与绝对温度成正比，AD590就是根据式(2 )工作的。 bcA D590的简化电路如图1所示 设T3、T4为理想三极管，将电流 I分成两部电流I = C1T I。由8个和Tl一样的三极管并联构成 T2所以T l 的电C2流密度JI 是 T

9、2的电流密度J2的8倍，两个相同的三极管流过不同的集电极电流I时，其V之差与绝对温度CBC成正比，即: V= V- V= KT,q?l n J l,J2 = K,q?( 1n8 )?T bc2bc1T,6=17910?T (3) ，由式 ( 3 ) 可知，V与T成正比， V是T 2管射极电阻TT由式 ( 3 ) 可知，V与T成正比，V是T2管射极电阻R上的压降，由于V与成正比所TTTR上的压降，由 于V与成正比， T以通过R上的电流I必与绝对温度T成正比，因I= 2 I，集成电路中的总电流I必与C2C2TTT成正比。 ,6,设R= 358，I= 2(17910,R )?T ，Tthe resp

10、onsible unit fined 200 Yuan, construction person in charge a fine of 50 Yuan. (8) no permit to work and the job in accordance with the provisions, on the job unit fined 300 yuan, the unit will charge a fine of 100 Yuan. 7.5.3 accident penalties (1) injuries fatalities directly punished 12 million. D

11、irect responsibility for the accident and have the corresponding responsibility of leadership, such as concerning administrative sanctions, should be brought to the company or the relevant Department. (2) personal injury accident occurred, the direct punishment 0.5-10,000 yuan, responsible for the d

12、irect responsibility for the accident and the responsibility of leadership, such as concerning administrative sanctions should be dealt with by the personnel Department of the company. (3) personal injury accident occurs, the direct punishment 500-1000, who is directly responsible for the accident r

13、esponsibility, give notice of criticism and 50-100 economic sanctions against them. (4) to conceal the accident, reported without undue delay or false, to inform the administrative leadership of the criticism, resulting in serious consequences, the pursuit of leadership, along with 500-1000 punishme

14、nt. (5) significant near miss should be attempted as the case of responsible for the accident and construction team injuries accident penalty provisions, mutatis mutandis. Eight, should perform in the construction standards and specifications, serial number a 1 GB3323-2005所以I/ T =lA,K ( 4 ) ,T这就是 A

15、D5 9 0当温度改变 l 度 ( 绝对温度)获得 l A电流输出的，这就是把温度转成电流的道理。 2 A D 5 9 0的应用电路 2.1基本应用电路 如图2是AD590用于测量热力学温度的基本应用电 路。因为流过A D 5 9 0的电流与热力学温度成正比， 当电阻R1和电位器 R P的电阻之和为1 k n时，输出 电压U0随温度的变化为1mV,K。但由于AD590的 图2测量热力学温度的基本应用电路 增益有偏差，电阻也有误差，因此应对电路进行调整， RP用于校准调整。调整的方法为:把AD590放于冰水混合物( 273.15 K )中，调整电位RP， 使U0 = 273.15 mV。或在室温

16、下( 298.15条件下调整电位器使U0 = 273.2 + 25 = 298 .2 m V。 但这样调整只可保证在 2 7 3. 1 5 K或2 9 8 .1 5 K附近有较高精度。 2.2模拟式摄氏温度测量电路 如图3 所示，电位器RP1用于调整零点，RP2用于调整运放的增益。调整方法如下: 在0?时调整 RP1，使输出Uo = 0，然后在 100?时调整 RP2使Uo = 100 mV。如此反复调整多次，直至0?时，Uo = 0 m V，100? 时Uo = 100 mV为止。最后在室温下进行校验。例 如，若室温为25 ?，那么Uo应为2 5 mV。冰水混合物是 0?环境，沸水为100

17、? 环境。 图3模拟式摄氏温度测量电路 2 .3数字式温度测量电路 AD590虽是一种模拟温度传感器，但附加上一些电路可输出数字信号。如图4所示，是由AD590和A /D转换器7106组成的数字式温度测量电路。电位器RP l用于调整基准电压， 以达满度调节;RP2 用于在0?时调零。当被测温度变化时通过R的电流不同，使得A点电位发生相应变化，检测此电位即能检测被测温度( AD590所在处温度)的高低。A点电the responsible unit fined 200 Yuan, construction person in charge a fine of 50 Yuan. (8) no pe

18、rmit to work and the job in accordance with the provisions, on the job unit fined 300 yuan, the unit will charge a fine of 100 Yuan. 7.5.3 accident penalties (1) injuries fatalities directly punished 12 million. Direct responsibility for the accident and have the corresponding responsibility of lead

19、ership, such as concerning administrative sanctions, should be brought to the company or the relevant Department. (2) personal injury accident occurred, the direct punishment 0.5-10,000 yuan, responsible for the direct responsibility for the accident and the responsibility of leadership, such as con

20、cerning administrative sanctions should be dealt with by the personnel Department of the company. (3) personal injury accident occurs, the direct punishment 500-1000, who is directly responsible for the accident responsibility, give notice of criticism and 50-100 economic sanctions against them. (4)

21、 to conceal the accident, reported without undue delay or false, to inform the administrative leadership of the criticism, resulting in serious consequences, the pursuit of leadership, along with 500-1000 punishment. (5) significant near miss should be attempted as the case of responsible for the ac

22、cident and construction team injuries accident penalty provisions, mutatis mutandis. Eight, should perform in the construction standards and specifications, serial number a 1 GB3323-2005位送入IC2的30脚，经7106 处理后，再送人显示电路驱动LED显示出被测温度。 图4数字式温度测量电路 2. 4温差测量电路及其应用 2 .4 .1温差测量原理分析 图5是利用两个AD590测量两点温度差的电路。两块AD59

23、0分别位于两个被检测点 B1、 B2。B1，B2处的温度-I= 分别为T1,T2，由图可得I =IT1T2K( Tl -T2 )。假设两块AD590有相同 T图5温差测量电路 的标度因子K T ，运放的输出Uo为U o = - IR3 = KR3 ( T1 - T2 ) 可见，整个电路总的标T 度因子为F =Uo/( Tl T2 ) = KR3，F值大小取决于R3。刚才假定了两块感温器件具有相同T的标度因子K，但实际上难免有差异，电路中设置电位器RP通过隔离电阻 Rl注入一个T校正电流 ?L 以获得平稳的零位误差。由校正前后的温度特性曲线可知，只有在某一温度 T时，有I=0 , 此点常设在量程

24、的中间。 2 .4 .2应用举例 (1)以某节能型药材仓库温、 湿度控制系统为例，若要求库房温度低于T?，相对湿度低the responsible unit fined 200 Yuan, construction person in charge a fine of 50 Yuan. (8) no permit to work and the job in accordance with the provisions, on the job unit fined 300 yuan, the unit will charge a fine of 100 Yuan. 7.5.3 accident

25、 penalties (1) injuries fatalities directly punished 12 million. Direct responsibility for the accident and have the corresponding responsibility of leadership, such as concerning administrative sanctions, should be brought to the company or the relevant Department. (2) personal injury accident occu

26、rred, the direct punishment 0.5-10,000 yuan, responsible for the direct responsibility for the accident and the responsibility of leadership, such as concerning administrative sanctions should be dealt with by the personnel Department of the company. (3) personal injury accident occurs, the direct p

27、unishment 500-1000, who is directly responsible for the accident responsibility, give notice of criticism and 50-100 economic sanctions against them. (4) to conceal the accident, reported without undue delay or false, to inform the administrative leadership of the criticism, resulting in serious con

28、sequences, the pursuit of leadership, along with 500-1000 punishment. (5) significant near miss should be attempted as the case of responsible for the accident and construction team injuries accident penalty provisions, mutatis mutandis. Eight, should perform in the construction standards and specif

29、ications, serial number a 1 GB3323-2005于A1B 1,RH 。则采取的两种控制模式如下: 控制模式一:当库内相对湿度高于A1B1,RH且库外温度低于T?时，进行库内外通风。这种方式是利用库内外湿度差进行空气的交换，以达到库内除湿的要求，其优点是高效、节能、节省资金。但这种方式受到严格的控制。首先，库外的相对湿度要低于库内的，它们之间的差要大于A2B2,RH，这样才能有效保证及时地进行库内的除湿。其次，库内库外的温度差要小于?T?，这是因为，如果在库外温度远高于库内温度时进行通风，热空气进入库区后遇上冷空气就会造成药品、器材表面结露的现象进而影响药品和器材的

30、质量。反之，如果在库内温度远高于库外温度时进行通风，冷空气进入库内后也会在药品器材表面结露。另外，库外温度不能接近T?。这是因为，如果库外温度接近T?时进行通风，很可能使密闭的库温升高，从而超过温度上限T?。 控制模式二 :当温度 高于 T ?或湿度高于 A1B1,RH但不满足第一种情况时，开启冷冻空调机组进行库内降温除湿。为避免因库内外温差过大通风时药品、 器材表面结露的现象，必须严格控制系统温差值的精度。传统的测温差方法是对两点温度分别进行处理(调理 电路、A,D、运算处理)后求差值，此方法所得温差精度低。库内外温差测量可采用图3所示电路，利用温差值直接与设定值相比较，既能保证较高的精度，

31、又简化了系统的软件设计， 提高了系统的可靠性。 (2)如图5所示的电路，运放的输出端Uo连接上报警电路，传感器B1设置在警戒液面的位置，传感器B2设置在警戒液面上方较远的位置。这样即成为了种液位报警器。平时传感器 B1、B2在相同的温度条件下调节电位器RP l使运放输出为零。当液面升高到警戒位时，传感器B1将会被液体淹没，由于液体温度与环境温度不同，因此运放输出控制电压Uo， 控制报警电路发出警报。 2.5 N点最低温度值的测量 将不 同测 温 点 上 的数 个 ADS 9 0相串联，可测出所有测量点上的温度最低值。该方法可应用于测量多点最低温度的场合。 2.6 N点温度平均值的测量 把 N个

32、 A D 5 9 0并联起来，将电流求和后取平均， 则可求出平均温度。该方法适用于需要多点平均温度但不需要各点具体温度的场合。 2.7 A D590在热电偶冷端补偿中的应用 热电偶有热端和冷端，它所产生的电动势为两者的热电势之差，因此同环境温度有关时，测量结果需要加以修正。利用AD5 9 0的线性温敏特性，可以给温差电偶的参考端 ( 冷端)the responsible unit fined 200 Yuan, construction person in charge a fine of 50 Yuan. (8) no permit to work and the job in accordance with the provisions, on the job unit fined 300 yuan, the unit will charge a fine of 100 Yuan. 7.5.3 accident penalties (1) injuries fatalities directly punished 12 million. Direct responsibility