Stability of a continuous-time state variable filter with op-amp and OTA-C integrators

Author

Bakken, Tim ; Choma, John

Author_Institution

Univ. of Southern California, USA

fYear

1998

fDate

19-21 Feb 1998

Firstpage

77

Lastpage

82

Abstract

The stability of a continuous-time state variable filter is analyzed using the Routh-Hurwitz criterion. This criterion assesses stability by indicating the number of poles that lie in the right-half plane. The filter is examined separately with integrators implemented with an op-amp and an OTA-C. Both amplifier types are characterized by a dominant-pole frequency response, and the stability of each implementation is compared. HSPICE simulations confirm the theoretical analyses, which indicate that the gain-bandwidth product of the op-amps and the bandwidth of the OTAs must be much larger than the desired frequency of operation to ensure stability. Since the analyses assume a dominant-pole response, all higher-order poles of the actual amplifier must also be much greater than the unity-gain frequency to minimize excess phase

Keywords

Routh methods; SPICE; circuit analysis computing; circuit stability; continuous time filters; digital simulation; frequency response; integrating circuits; HSPICE simulations; OTA-C integrators; Routh-Hurwitz criterion; continuous-time state variable filter; dominant-pole frequency response; gain-bandwidth product; higher-order poles; stability; Analytical models; Bandwidth; Circuits; Filters; Frequency response; Operational amplifiers; Stability; Stability analysis; Stability criteria;

fLanguage

English

Publisher

ieee

Conference_Titel

VLSI, 1998. Proceedings of the 8th Great Lakes Symposium on

Conference_Location

Lafayette, LA

ISSN

1066-1395

Print_ISBN

0-8186-8409-7

Type

conf

DOI

10.1109/GLSV.1998.665203

Filename

665203