A reduction in the number of active components used in transconductance grounded capacitor filters

Abstract

The number of active components in transconductance grounded capacitor filters is reduced. This reduction is possible in the case where capacitor loops and/or inductor cutsets exist in LC-ladder prototype. A more significant reduction is obtained in the OTA-C (operational transductance amplifier-capacitor version. The number of OTAs is reduced to 7 from 13 while the total capacitance value remains intact. It is also important to note that all transconductance elements or OTAs are identical except possibly one. The only drawback of this reduction is implementation of some floating capacitors instead of all grounded capacitors.