Analysis of SAR ADC Performance Enhancement Utilizing Stochastic Resonance

Stochastic resonance (SR) is a phenomenon where the noise of a certain intensity helps to improve the signal-to-noise ratio (SNR) of nonlinear systems. This brief applies this concept to a successive approximation register (SAR) analog-to-digital converter (ADC) to enhance its performance. To improve the effective number of bits of the SAR ADC, some additional comparisons are repeated after the normal binary search. The theoretical analysis of the performance enhancement based on the statistical information provides the optimal number of additional comparisons in terms of the ADC figure-of-merit (FoM). As this scheme allows the use of a high-input-referred-noise but low-power comparator in the SAR ADC, the total power consumption can be reduced even with the additional comparisons.