A fully balanced differential GaAs MESFET OTA-C integrator suitable for high precision filtering applications

Describes a fully balanced, differential input, version of the variable gain operational transconductance amplifier (OTA) presented in, which lends itself particularly well to fully balanced architecture, in which the low gain inherent in MESFET OTAs is overcome by means of a novel, variable bootstrapping technique. The basic performance parameters of this integrator are reported. although the circuit performs well as an OTA, featuring excellent bandwidth and linearity, there are considerable, well understood advantages in employing a fully differential realisation of such a system. An examination of the circuit reveals that it lends itself particularly well to a fully differential form since both the transconductance amplifier and bootstrap amplifier are based on symmetrical differential pair configurations and so relatively few extra components (and hence little extra power consumption) are required