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Switched-Capacitor Track-and-Hold Amplifiers With Low Sensitivity to Op-Amp Imperfections

TitleSwitched-Capacitor Track-and-Hold Amplifiers With Low Sensitivity to Op-Amp Imperfections
Publication TypeJournal Article
Year of Publication2007
AuthorsYoshizawa, H., and G. C. Temes
JournalIEEE Transactions on Circuits and Systems I: Regular Papers
Pagination193 - 199
Date Published01/2007
Keywordsanalog signal processing, switched-capacitor (SC) amplifier, track-and-hold (T/H) stage

This paper describes high-precision switched-capacitor (SC) track-and-hold amplifier (THA) stages. They use a novel continuous-time correlated double sampling (CDS) scheme to desensitize the operation to amplifier imperfections. Unlike earlier predictive-CDS amplifiers, the circuits do not need a sampled-and-held input signal for their operation. During the tracking period, an auxiliary continuous-time signal path is established, which predicts the output voltage during the holding period. This allows accurate operation even for low amplifier gains and large offsets over a wide input frequency range. Extensive simulations were performed to compare the performance of the proposed THAs with earlier circuits utilizing CDS. The results verify that their operation is far more robust than that of any previously described SC amplifiers.

Short TitleIEEE Trans. Circuits Syst. I