Patent ID: 7710303

Claim:
A mixed signal device having an analog-to-digital converter that is calibrated using internal voltage references, comprising: a digital processor; an analog-to-digital converter (ADC); an analog multiplexer; a voltage divider connected to a power supply voltage and deriving a plurality of different voltage values from the power supply voltage and supplying two of the plurality of different voltages, Y 1 and Y 2 , to two inputs of the analog multiplexer; the ADC is connected to an output of the analog multiplexer and to the digital processor, and the ADC converts the two of the plurality of different voltage values, Y 1 and Y 2 , to digital voltage values, X 1 and X 2 , respectively, and sends the digital voltage values, X 1 and X 2 , to the digital processor; wherein the digital processor calculates gain, m, and offset, c, values required for calibrating the ADC output by using the two of the plurality of different voltage values, Y 1 and Y 2 , as voltage reference points to solve for m and c in equations: Y 1 =m*X 1 +c and Y 2 =m*X 2 +c.