HomeDesign GuideDesign Guide Details
Design Guide Details
Date: 03-01-17

Sensor circuits

Sensor circuits

Temperature measurement using thermistor and an ADC

The thermistor is used to detect the change in temperature. There are two types of thermistor, Positive Temperature Coeffecient (PTC) and Negative Temperature Coeffecient (NTC). In PTC type,the resistance increase with temperature and in NTC type, the resistance decrease with temperature. Change in resistance can be converted into electric signal and this analog signal can be converter into digital output using Analog to Digital Converter (ADC).

The conceptual circuit diagram is as shown below


Circuit Diagram (Schematic Diagram)-1

Use these equations to design your circuitry by selecting thermistor and ADC from any of these vendors given far below


N = ADC resolution
b0, b1, and b3 are the temperature coefficients of thermistor.

This is one of the fundamental concept, there are many new innovative idea from the vendors below. Please refer their websites
ADC vendors
MAXIM www.maxim-ic.com
Analog Device www.analog.com
National Semiconductor www.national.com
Texas Instruments www.ti.com
Thermistor vendors
AdSem, Inc. www.adsem.com
EPCOS www.epcos.com
Nichicon USA www.nichicon-us.com
NIC Components www.niccomp.com

Selected list of sensor related analog circuits from multiple vendors.

Default user
Related Design Guide Articles