The temperature sensor has four main types: thermocouple, thermal resistance, resistance temperature detector ( RTD) And the IC temperature sensor ( See table below) 。 IC temperature sensor and includes two types, that is, analog output and digital output.

thermocouple is widely used, because they were very strong and not too expensive. There are different types of thermocouple, they cover a wide temperature range, from - 200 ℃ to 2000 ℃. Their features are: low sensitivity, low stability, moderate accuracy, and easy to aging and slow response speed, high temperature drift, and nonlinearity. In addition, the thermocouple need external reference.

RTD precision is high and medium linearity. They are particularly stable, and there are many kinds of configuration. But they are the highest working temperature can reach 400 ℃ or so. They also have a lot of TC, and expensive ( 4 ~ 10 times that of thermocouples) And require an external reference source.

analog output IC temperature sensor of high linearity, If an AD converter or ADC can produce digital output) , low cost, high precision, About 1 [ ( %) ] ) , small size and high resolution. Their shortcoming in the temperature range co. , LTD. ( - 55℃～＋150℃) And require an external reference source

digital output IC temperature sensor with a built-in reference source, their response is quite slow, The order of magnitude of 100 ms) 。 Although they will inherently itself fever, shut down automatically and can be used before a single conversion mode in the need to measure the state of IC is set to the low power consumption, so as to minimize their fever.

compared with thermistors, RTD and thermocouple sensor, has the very high linear IC temperature sensor, low system cost, the integration of complex function, can provide a digital output, and can be within a fairly useful for temperature measurement.