Title :
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
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;
Conference_Titel :
VLSI, 1998. Proceedings of the 8th Great Lakes Symposium on
Conference_Location :
Lafayette, LA
Print_ISBN :
0-8186-8409-7
DOI :
10.1109/GLSV.1998.665203
