| Autor: |
Bos, Lynn, Vandersteen, Gerd, Rolain, Yves |
| Přispěvatelé: |
Electronics and Informatics, Electricity |
| Jazyk: |
angličtina |
| Rok vydání: |
2007 |
| Předmět: |
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| Popis: |
Analog discrete-time systems are becoming more important in deep-submicron CMOS technologies [1]. These systems are based on switched-capacitor (SC) technologies where the sampling switches, driven by a periodic clock, make the overall system periodic time-varying (PTV). The PTV behaviour results into the frequency folding of frequency components higher than the Nyquist frequency. The nonlinear distortion of nonlinear time-invariant systems can be quantified and qualified using a random phase multisine (MS) with a user defined amplitude spectrum [2]. A random phase MS is a sum of harmonically related sines with each a random phase between 0,2Pi. A random odd MS is an odd MS where 1 random odd frequency line in a group of consecutive odd lines is not excited. This enables the measurement of the even and odd nonlinearities (NL) on the respectively even and non-excited odd lines in the output spectrum. These non-excited lines are the so-called detection lines [1]. Random odd MS can't be used straightaway for PTV systems. The non-excited detection lines of a random odd MS do not only contain the nonlinear contributes, but also the aliasing components due to the frequency folding introduced by the PTV behaviour of the system. This paper introduces an analysis with a specially designed MS for PTV systems in Section II which enables the separation of the different linear and nonlinear contributions. The concept of the best linear approximation is extended towards PTV systems in Section III. This makes it possible to determine the conversion matrix of the best linear PTV approximation of the circuit. The technique is illustrated using transistor-level simulations on a 5th order SC filter. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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