Digital temperature sensors and calibration thereof

A digital temperature sensor uses an analogue temperature detector, an internal reference voltage, and an analogue-to-digital converter (ADC). The ADC compares the temperature signal with the reference voltage to calculate the ambient temperature. During calibration, the system measures the internal reference voltage and compares it with the desired value. It then adjusts the reference voltage source to correct any difference. This electrical calibration is faster and cheaper than calibrating the sensor at different temperatures, and can be used with PTAT sensors and bandgap reference voltages.