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AN78920 - PSoC® 1 Temperature Measurement Using Diode | Cypress Semiconductor

AN78920 - PSoC® 1 Temperature Measurement Using Diode

Last Updated: 
Aug 26, 2015

AN78920 explains the diode-based temperature measurement using PSoC® 1 – CY8C28xxx family. The temperature is measured based on the principle of a diode’s forward bias current dependence on temperature.


PSoC 1 – CY8C28xxx family has on-chip 8-bit IDAC, and a 14-bit Delta Sigma ADC, which enable accurate and highresolution temperature measurements using an external diode-connected transistor. The example projects attached with this application note work with CY8CKIT-036 – PSoC Thermal management EBK.

There are various sensors available for measuring temperature such as Thermistor, Thermocouple, resistance temperature detectors (RTD). Choosing a sensor or method to employ for measuring the temperature depends on factors such as the accuracy requirement, the temperature range to be measured, and the cost of the temperature sensor. The diode based temperature measurement is an easy, accurate, and also relatively low-cost method for measuring the temperature. With on-chip current DACs and a 14-bit Delta Sigma ADC, PSoC 1 – CY8C28xxx family enables simple and accurate temperature measurement using just an external diode and a calibration resistor. With 14-bit Delta Sigma ADC, it is possible to achieve resolution of 1 °C, and an accuracy of ±2 °C in temperature measurement.