Patent ID: 7973693
Filing Date: 2011-07-05
Classification: H03M

Abstract:
1. A circuit comprising a successive approximation analog to digital converter, comprising: a signal input for receiving an analog input signal; a reference signal generator having a control input and an analog reference signal output; a comparator having a first and second comparator input, coupled to the signal input and the analog reference signal output respectively, and a comparator output for supplying a comparator output signal; and a control circuit having an input coupled to the comparator output and a control output coupled to the control input of the reference voltage generator, the control circuit being configured to indicate a series of digital reference values at the control input of the reference signal generator in successive recursion cycles, with steps between successive digital reference values, wherein the control circuit is configured for selecting successive ones of the steps, such that each step comprises a step size dependent on values of the comparator output signal from a plurality of preceding recursion cycles.