Parasitic-insensitive switched-capacitor all-pass filters having low amplitude sensitivity

Autor: Tsuyoshi Takebe, Satoshi Sekiguchi, Nobuaki Takahashi
Rok vydání: 2000
Předmět:
Zdroj: Electronics and Communications in Japan (Part III: Fundamental Electronic Science). 84:84-94
ISSN: 1520-6440
1042-0967
DOI: 10.1002/1520-6440(200101)84:1<84::aid-ecjc9>3.0.co;2-r
Popis: This paper proposes a realization of first- and second-order switched-capacitor (SC) all-pass filters (APF) with a low amplitude sensitivity and a parasitic capacitor insensitivity. Kato and Takebe have proposed a first-order SC APF where the peak group delay for the zero angular frequency can be defined by means of a programmable capacitor array, as well as a second-order SC APF with the first-order SC APF as a partial subcircuit, where the peak value of the bandpass group delay and the corresponding angular frequency (peak angular frequency) can be defined independently. Their second-order SC APF has the problem that the amplitude element sensitivity is large and the response is sensitive to parasitic capacitance. The SC APFs proposed in this paper are insensitive to parasitic capacitance, and the absolute value sum of the amplitude sensitivities is very small, being 0 in the first-order SC APF and less than 2 in the second-order SC APF. Further, the number of operational amplifiers is reduced by 1 and the number of capacitors is halved in the proposed second-order SC APF, compared to the already proposed circuits. The proposed circuit is experimentally constructed by discrete components, and a satisfactory result is obtained. © 2000 Scripta Technica, Electron Comm Jpn Pt 3, 84(1): 84–94, 2001
Databáze: OpenAIRE
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