Averaging Technique – Transient Analysis and Automated Design

The dynamic behavior of pre-amplifier stages using averaging is analyzed in this chapter: the output voltage expression presented in the previous chapter (2.19), is extended to s-domain, allowing the evaluation of the time-domain response. This is fundamental for the automatic design and high-level modeling of flash ADCs. To the best knowledge of the authors, there is no previously published research work covering this subject.

Examples of high-level modeling of data converters can be found in [7, 50, 107, 108]. These models allow to assess the impact of the parameters of each constituting sub-block in the global performance of the converter, or even on the system where it will be used. To get, from these models, results as near the reality as possible, each sub-block of the converter must be accurately modeled, including as many non-idealities as possible. The analysis of non-idealities, like the ones presented in [25, 90, 107–109] and at this book are, thus, of great relevance. In fact, the expressions presented in this chapter model the transient behavior of averaged pre-amplifying stages accurately. This includes the effect of all mismatch sources and, therefore, completely characterizes their operation. This is a clear evolution with respect to previous approaches [25], where fitting functions had to be obtained from SPICE simulations.