RESEARCH ARTICLE High performance voltage output filter realizations using second generation voltage conveyor Leila Safari | Gianluca Barile | Giuseppe Ferri | Vincenzo Stornelli Department of Industrial and Information Engineering and Economics, University of L'Aquila, L'Aquila, Italy Correspondence Gianluca Barile, Department of Industrial and Information Engineering and Economics, University of L'Aquila, L'Aquila, Italy. Email: gianluca.barile@graduate.univaq.it Abstract In this article, new voltage-output filter realizations based on second generation voltage conveyor (VCII) as basic building block are presented. The results of this study show that VCII is a suitable candidate for applications requiring a voltage as filter output signal, considering that the availability of a low impedance voltage output terminal in VCII makes unnecessary the use of extra voltage buffers at the filter output, resulting in filter implementations with simpler structure, reduced power consumption, and chip area. New configurations of VCII based filters with first order low-pass (LP), second order LP, and second order bandpass (BP) transfer functions are shown. The proposed circuits enjoy a very simple struc- ture employing only one active element and four passive components. Simulation results for a VCII transistor implementation in a 0.35 μm standard CMOS technol- ogy and a supply voltage of 1.65 V approve the presented theory. KEYWORDS current conveyor, current mode filter, low pass filter, low voltage filter, voltage conveyor, voltage-mode filter 1 | INTRODUCTION Active filters play a fundamental role in analog signal processing. 1–10 They are used in various areas like commu- nication, measurement, instrumentation, and control sys- tems. The traditional method of implementing active filters is based on op-amps, resistors and capacitors which is not attractive anymore. The apparent drawbacks of this method are high power consumption, large supply voltage require- ment and poor frequency performance. However, the low- voltage low-power operation is highly demanded in portable and battery-powered applications. 11–13 In addition, for mixed-mode configurations in which analog filters are inte- grated with digital sections, the supply voltage requirement must be in the range of allowable values in deep-sub-micron and nanometer CMOS technologies. In recent years, the application of current-mode (CM) signal processing in filter design has received remark- able attention. 1–10 In CM circuits, the nodes impedances are low and the processed signals are currents which are not limited by supply voltages making this method highly suit- able for low voltage design. 14 In addition, due to inherent high frequency performance and simplicity of CM signal processing, CM filters consume low power and require low chip area for a given frequency. Profound investigations showing different kinds of filters have been designed using second generation current con- veyors (CCIIs) and other current mode active building block. 1–10 Despite their numerous advantageous, most of the current conveyor-based filters suffer from a serious draw- back in applications requiring voltage output. For example, Figure 1 shows two CM filters, based on CCIIs, in voltage- input voltage-output (a) and current-input voltage-output (b) configurations. 8,10 As it is seen from Figure 1, for practi- cal applications, extra voltage buffers (not shown) are required at the output nodes to ensure a low impedance. This is the evident weakness of current conveyors for voltage- output applications. It is apparent that for voltage-output applications, a new building block with voltage output capability is advantageous. Received: 26 April 2018 Revised: 9 August 2018 Accepted: 10 August 2018 DOI: 10.1002/mmce.21534 Int J RF Microw Comput Aided Eng. 2018;e21534. wileyonlinelibrary.com/journal/mmce © 2018 Wiley Periodicals, Inc. 1 of 7 https://doi.org/10.1002/mmce.21534