Analyzing and modeling the performance degradation of flash A/D converters due to substrate noise coupling

作者：Stefanou Athanasios^*; Gielen Georges

来源：Analog Integrated Circuits and Signal Processing, 2010, 65(2): 185-195.

DOI：10.1007/s10470-010-9475-7

• Substrate noise
• Distortion
• Flash analog-to-digital converter (ADC)
• Regenerative comparator
• Non-uniform sampling

This paper presents a model to evaluate the impact of substrate noise on a CMOS regenerative comparator and moreover to predict the resulting performance degradation of a flash analog-to-digital (A/D) converter. The proposed approach initially relates substrate noise to the induced timing uncertainty of the comparator by means of an analytical linear model. In particular, the analysis first focuses on analyzing and expressing the resulting non-uniform sampling distortion in regenerative comparators in the presence of a deterministic ground bounce. Two sources of distortion are identified and evaluated: the input-dependent and the substrate noise-dependent one. For each error contributor, the analysis investigates two cases of timing error, based on the frequency correlation of the interfering signal with the sampling clock. The properties (number and power of distortion tones) of the sampling error spectrum are found to be highly dependent on the spectral content of the interfering signal and the sampling clock, while the model captures accurately the induced distortion. Subsequently, the linear model is extended to estimate the degradation of flash A/D converters and is utilized to predict the performance of practical flash and time-interleaved converters in the presence of substrate noise.

• 出版日期2010-11