Design of aCMOSTunable Bandpass Filter with a New Active VD-gm Amplifier Floating Inductor

Abstract

Background/Objectives: The VD-gm amplifier is a flexible method of converting passive to active circuit. In this paper, a new VD-gm amplifier floating inductor is proposed for realizing active CMOS bandpass filter.

Methods/Statistical analysis: This proposed method uses only one VD-gm and one gm for designing an active floating inductor from a passive floating inductor instead of thetypical method using two VD-gms.

Findings: By the proposed method, the number and the power consumption of internal transistors can be reduced. The HSPICE simulation confirmed that the proposed VD-gm amplifier floating inductor can be applied to the design of second order active CMOS adjustable bandpass filter from 600kHz to 1.4MHz. Improvements/Applications: Simulation results showed that the new VD-gm amplifier floating inductor can be very useful in designing a CMOS tunable bandpass filter that reduces the size of a circuit.

Keywords: VD-gm amplifier, Floating inductor, Active inductor, Active filter, Transconductance