單迴路積分三角類比數位轉換器之積分器充電雜訊與諧波功率模型

Abstract

交換式電容積分器是積分三角轉換器中基本的建構成份。其電容不完全的充放電轉換特性(積分器充放電問題)為積分三角轉換器中一個主要影響輸出誤差的來源。而因為積分器充放電問題的高複雜性,相關的誤差和失真的解析模型實際上是不存在的。在此篇論文中,我們的目的在於經由非線性擬合方法和輸出端頻譜預測技術來分析積分器充放電問題。由上法,積分器充放電問題誤差和失真的封閉解可獲得,且可使用積分三角轉換器中的系統參數來組成函數以呈獻出來。同時我們使用了行為層的模擬以及HSPICE電路的模擬來驗證此解析模型的正確性,驗證結果顯示出我們的解析模型是足夠精確的。

Switch-capacitor (SC) integrator is the basic building component for sigma-delta ( ) modulators and its incomplete charge transfer (settling problem) constitutes one of the dominant error sources in modulators. Due to the complexity of settling problem, analytic models for related noises and distortions are virtually non-existent. In this paper, we aim to analyze the settling problems by employing nonlinear fitting methods and output spectrum prediction techniques. Closed forms of settling error and settling distortion models are obtained, and are represented as functions of modulator system parameters. Both behavior simulations and HSPICE circuits are employed to verify these analytical models, and the results show that our analytical models are sufficiently accurate.