Hi, I have an AD592 temperature sensor, to create a temperature probe, but I don't understand why the middle pin is not used, how do I receive the information from the sensor?. I have read the datasheet but I can't find the answer.
The data sheet shows a circuit for it. The sensor provides variable resistance between the + and - pins so you use a voltage divider to read it.
The AD592 is a two-terminal integrated circuit temperature transducer that generates an output current proportional to the absolute temperature. For supply voltages between 4 V and 30 V, the device provides high impedance with a linear current output of 1 μA/K. You can power it with a pull up resistor to 5 volts, try 10K. Connect connect ground to ad592, Connect analog x to ad592 and resistor junction. You can connect it with the AD592 connected to +5 and the resistor to ground if you like as shown in schematic. This sensor can be at the end of a long wire as it is a current not a voltage device. The resistor converts the current to voltage so you can use it.
The 592 has been around for years , ( used one in early 1980’s) -one of the problems is the sensitivity and offset .
You have ~293uA at ambient temperature and an increase of only 1uA per degC.
So typically you need amplification to get a sensible range of temperature readings and get rid of the offset , when using a load resistor to generate a voltage from it .
EG: a with just a 10k load resistor, it would produce around 2.93 volts at ambient , but only 0.01volts change per deg C , so not great to feed into an Arduino A/D which would only then see an change of around 5C. ( as it resolves to 5/1023=~ 0.05v)
Suggested circuit here , shows typically the extra bits you need :
Something like a DS18B20 might be better for you .
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