US Patent 7352306 Analog-to-digital converter with non-linearity compensation

Systems and techniques for converting an analog input value to an output digital code are described. A system includes a first internal analog-to-digital converter (ADC) configured to receive the analog input value and to convert it to a first digital code; a first internal digital-to-analog converter (DAC) configured to convert the first digital code to a first analog value; a first linearization module configured to receive the first digital code and to produce a first linear-correction code that is approximately equal to the first analog value; a second internal ADC configured to convert a remainder portion of the analog input value to a second digital code; and an accumulator configured to combine the first linear-correction code and the second digital code to produce the output digital code.