Transadmittance Type Universal Current-Mode Biquad Filter Using VDTAs.

Dinesh Prasad,Mayank Srivastava,D R Bhaskar

doi:10.1155/2014/762845

Dinesh Prasad, Mayank Srivastava + Show 1 more

Open Access

https://doi.org/10.1155/2014/762845

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Abstract

A new resistorless single-input-multi-output (SIMO) universal transadmittance (TA) type filter employing two voltage differencing transconductance amplifiers (VDTA) and two grounded capacitors is proposed. The proposed topology realizes simultaneously low pass (LP), high pass (HP), and band pass (BP) filter functions. Band rejects (BR) and all pass (AP) filters are also realizable through appropriate connections of currents. The proposed configuration also offers independent control of natural angular frequency (ω 0) and bandwidth (BW) and low active and passive sensitivities. The workability of proposed configuration has been demonstrated through PSPICE simulations with TSMC CMOS 0.18 μm process parameters.

Highlights

Multifunction filters are getting significant attention in current analog IC design due to their versatility as the same configuration can be used for various filter responses
SIMO type active filters employing different active building blocks/devices are available in both current mode (CM) and voltage mode (VM)
Taking into account the various voltage differencing transconductance amplifiers (VDTA) parasitics such as the finite P-terminal parasitic impedance consisting of a resistance RP in parallel with capacitance CP, the finite N-terminal parasitic impedance consisting of a resistance RN in parallel with capacitance CN, the finite X-terminal parasitic impedance consisting of a resistance RX in parallel with capacitance CX, and the parasitic impedance at the Z-terminal consisting of a resistance RZ in parallel with capacitance CZ, the ω0 and Q0 including the influence of parasitic are given by ω0

Summary

Introduction

Multifunction filters are getting significant attention in current analog IC design due to their versatility as the same configuration can be used for various filter responses. A universal current-mode biquad filter using single VDTA has been reported in [13] and grounded and floating inductance circuits using single/two VDTAs and one grounded capacitor have been proposed in [10]. In this communication, we present a new configuration for realizing TA universal biquadratic filter with one input and three outputs. The proposed new circuit offers various features such as employment of only two VDTAs, two grounded capacitors, simultaneous realization of LP, HP, and BP filtering responses without changing circuit topology, independent control of ω0 and BW, and low active and passive sensitivities. The workability of the proposed TA filter has been verified by SPICE simulations with TSMC CMOS 0.18 μm process parameters

The Proposed Transadmittance Filter

Nonideal Analysis and Sensitivity Performance

Simulation Results

Conclusion