Error Measurement and Calibration of Analog to Digital Converters

Abstract

Methods of measuring capacitance error in a successive approximation register (SAR) analog to digital converter (ADC) are described, including a method in which said ADC includes a register and a digital to analog converter (DAC), and the method comprises connecting a first capacitance associated with a first bit of the DAC between a first reference voltage and a second reference voltage, connecting a first set of one or more capacitances associated with one or more other bits of the DAC between the first reference voltage and a third reference voltage, connecting the first capacitance between a first node and the third reference voltage, connecting the first set of one or more capacitances between the first node and the second reference voltage, and measuring a voltage at the first node to determine a representation of a difference between the first capacitance and a total capacitance of the first set of one or more capacitances.

Dependencies are inferred from the claim text.