Title :
Dynamic currents in log-domain filters
Author :
Fox, R.M. ; Ko, H.J. ; Eisenstadt, W.R.
Author_Institution :
Dept. of Electr. & Comput. Eng., Florida Univ., Gainesville, FL, USA
Abstract :
Single-ended log-domain filters must operate class A: the amplitude of any symmetric signal must be less than the bias current. Even so, internal dynamic current requirements can be much higher than the bias currents. Worst-case peak current demands are related to the modulation index by simple expressions that allow transistor geometries to be optimized for specified signal levels. Some circuit topologies are shown to be better able to supply large internal currents than others
Keywords :
active filters; current-mode circuits; electric current; linear network analysis; linear network synthesis; transfer functions; bias currents; circuit topologies; class-A operation; dynamic currents; log-domain filters; modulation index; single-ended filters; specified signal levels; transistor geometries optimisation; Band pass filters; Capacitors; Circuit simulation; Circuit topology; Cutoff frequency; Design engineering; Filtering theory; Modulation; USA Councils; Voltage;
Conference_Titel :
Circuits and Systems, 1999. 42nd Midwest Symposium on
Conference_Location :
Las Cruces, NM
Print_ISBN :
0-7803-5491-5
DOI :
10.1109/MWSCAS.1999.867795
