A Method for ADC Error Testing and its Compensation in Ratiometric Measurements

Errors induced due to ratiometric measurements are discussed and a simplified compensation method to reduce the various static errors of ADC, voltage reference errors in ratiometry and resistance mismatch errors is proposed. Curve fitting is done for the error samples and the system is modelled in comparison to an ideal system. Static errors and other ratiometric errors, thus modelled are derived into a corrective equation in comparison with an errorless system. Implementation of the proposed method is discussed for a resistance measurement system and analyzed. This paper also discusses the usage of the proposed system with successive approximation ADCs for ratiometric measurement operations against the conventional requirement dual slope ADCs for the same.