Tunable frequency versatile filters implementation using minimum number of passive elements

Abstract

Two new universal active current-mode filters are proposed, one topology of which is with three inputs and one output, the other prototype is with single input and three outputs counterpart. One proposed circuit employs two current conveyors, two grounded capacitors and two resistors, wherever the other proposed circuit employs two current conveyors, two grounded capacitors and two multiinput, multi-output Operational Transconductance Amplifiers(OTA) as variable resistor for tuning the cutoff frequency of realized filters. Without changing the passive elements, the proposed circuits employ features of multifunctional, convenient for integration, low sensitivities and simple in structure.

Fully Digitally Programmable Generalized Mixed Mode Universal Filter Configuration

“…Apart from this, the proposed CM UF is suitable for very high frequency application as all the parasitic capacitances of CCs are absorbed in the external capacitances of UF. UFs of [14] use exactly equal number of active (both proposed and reported UFs use one MOCC and one negative CCII) and grounded passive components. However, it is not insensitive to parasitics.…”

MOSFET-only multi-function biquad filter

“…Later, current-mode active elements such as current conveyors became increasingly popular due to their high frequency performance [1]. Researchers focused on different features, such as low voltage operation or good high frequency performance, component count etc., and they presented many other circuits [2][3][4][5][6][7]. Although these circuits provide sufficient high performance compared to classical active filters, they may not answer requirements of gigahertz range applications.…”

“…The proposed filter circuit is easy to tune. When compared to filter circuits realized with active and passive elements [2][3][4][5][6][7], the proposed circuit employs very fewer transistors with reduced power consumption and layout area and also extended operating frequency. The presented circuit is attractive compared to [9][10][11][12] considering the device modeling difficulties [11] of MOSFET distributed RC circuits.…”