Diode Temperature Sensors
These sensors are made up by using regular PN junction diodes. These are the most inexpensive type of temperature sensors which are competent enough to provide very adequate results if constant and steady excitation current is supplied to them. Also, they need a two point calibration for satisfactory operation. An ordinary semiconductor diode provides a sensibly linear forward biased voltage whose temperature coefficient is around 2.3mV/°C. A typical diode temperature sensor is shown in the figure below.