IEEE Journal of Solid-State Circuits · 2011 · 70 citations · 16 references
EngineeringElectrical EngineeringAnalog ElectronicsLow-power DesignMicroelectronicsActive FiltersAnalog FiltersAnalog Integrated CircuitsAnalog IntegrationCmos Circuit DesignMixed-signal Integrated Circuit DesignActive Rc FiltersBandwidthChebyshev Active FiltersCmos Analog Integrated CircuitsGm-c FiltersOperational Transconductance AmplifiersTransconductanceTransconductance Amplifiers
The linearity of conventional active-RC filters is limited by the operational transconductance amplifiers (OTAs) used in the integrators. Transconductance-capacitance (Gm-C) filters are fast and can be linear- however, they are sensitive to parasitic capacitances. We explore the Gm-assisted OTA-RC technique, which is a way of combining Gm-C and active-RC integrators in a manner that enhances the linearity and speed of the latter, while adding negligible extra noise or power dissipation. Measurements from a fifth-order Chebyshev filter with 20 MHz bandwidth, designed in a 0.18 μ m CMOS process, demonstrate the efficacy of Gm-assistance in an active-RC integrator.
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