A multiplexed switched capacitor filter bank
- 1 December 1980
- journal article
- Published by Institute of Electrical and Electronics Engineers (IEEE) in IEEE Journal of Solid-State Circuits
- Vol. 15 (6), 939-945
- https://doi.org/10.1109/JSSC.1980.1051500
Abstract
A technique is introduced which allows several integrator capacitors to be multiplexed onto a single operational amplifier. As a result, the op amp can be shared by several switched capacitor filter channels, drastically reducing the number of op amps required for filter banks. Twenty second-order filters have been implemented in a circuit using only two op amps and 2.5 mm/SUP 2/. The design of this system is presented and its performance is discussed. Some loss of signal energy is shown to occur during the multiplexing operations, which reduces filter Q. Causes of this charge loss are described, and its effects on performance are modeled. The design of the op amp used is presented, which incorporates a new system of input stage biasing and differential to single-ended conversion, as well as other features.Keywords
This publication has 6 references indexed in Scilit:
- The JSRU channel vocoderIEE Proceedings F Communications, Radar and Signal Processing, 1980
- A multiplexed switched capacitor filter bankPublished by Institute of Electrical and Electronics Engineers (IEEE) ,1980
- A process insensitive NMOS operational amplifierPublished by Institute of Electrical and Electronics Engineers (IEEE) ,1979
- A monolithic 512 point chirp Z transform processorPublished by Institute of Electrical and Electronics Engineers (IEEE) ,1979
- An NMOS operational amplifierPublished by Institute of Electrical and Electronics Engineers (IEEE) ,1979
- MOS sampled data recursive filters using switched capacitor integratorsIEEE Journal of Solid-State Circuits, 1977