Measurement and enhancement of multistage sigma-delta modulators

• Autorzy: Hejn K. , Murphy P. , Kale I.
• Języki publikacji: EN

Abstrakty

EN

Over-sampled sigma-delta modulators are at present the only solution to realizing high resolution (>16 bits) A/D converters. They are relacively robust against circuit imperfections and well suited for VLSI implementation. Their theoretical basis is well founded in many excellent papers. However, it has to be pointed out that those analyses have not considered effects such as gain mismatch of the stages, timing. Ditters, input noise. Instability of thresholders the asymmetry in the rise fall times of the pulses generated etc. Knowing sigma-delfa modulators theory is not the same as knowing what to do when asked to measure a signal spectrum with 1 dB resolution or -130 dB harmonic distortion. These numerical values are typical for sigma-delta structures with 20-bit potential. This paper specifically addresses such problems suggests some solutions. Simulations known that the key factors are: a coherent measurement event (explicit) digitizing and polyphase recursive all-pass filtering.

Słowa kluczowe

EN

multistage modulators; sigma-delta modulator; mixed-signal circuits

PL

modulatory wielostopniowe; modulator sigma-delta; mieszane-sygnałowo układy scalone

• Wydawca: Przemysłowy Instytut Elektroniki
• Czasopismo: Prace Przemysłowego Instytutu Elektroniki
• Rocznik: 1998
• Tom: nr 132
• Strony: 18--24
• Opis fizyczny: Bibliogr. 10 poz., rys., tab., wykr.

Twórcy

autor

Hejn K.

autor

Murphy P.

autor

Kale I.

• Institute of Electronics Fundamentals, Warsaw University of Technology, Nowowiejska 15/19, 00-665 Warsaw, Poland