Application Note

IC Temperature Sensor Accuracy Compensation With A PICmicro Microcontroller

Source: Microchip Technology Inc.

Microchip Technology Inc. provides a number of analog and serial-output Integrated circuit (IC) temperatures sensors. The typical accuracy of these sensors at room temperature is within one degree Celsius (±1C). However, at hot or cold temperature extremes, the accuracy decreases non-linearly. Typically, the non-linearity has a parabolic shape. This application note derives an equation that describes the sensor’s typical non-linear characteristics, which can be used to compensate for the sensors accuracy error over the specified operating temperature range. A PICmicro® Microcontroller Unit (MCU) can be used to compute the equation and provide higher-accuracy temperature reading. This application note is based on the analog output MCP9700/MCP9701 and serial output MCP9800 temperatures sensors.