Method and apparatus for performing voltage sampling

摘要

Method and apparatus for performing voltage sampling. The present invention addresses the problems encountered when a voltage is applied to a voltage sampling circuit (76). An additional capacitor (88) is used to store an amount of charge similar to the amount of charge needed by a primary capacitor (89) which provides an output signal to a voltage receiving circuit (74), such as a portion of a sigma-delta analog to digital converter. The additional capacitor (88) is charged while a primary capacitor (89) is discharged in a first clock phase. Then the additional capacitor (88) and the primary capacitor (89) are both coupled to the voltage to be sampled during a second clock phase.