A New Realization of Electronically Tunable Multiple-Input Single-Voltage Output Second-Order LP/BP Filter Using VCII

Abstract

In this paper, a new realization of electronically tunable voltage output second-order low-pass (LP) and band-pass (BP) filter is presented. The circuit has a multiple-input single-output structure, and LP and BP outputs are provided using the same structure. One electronically variable second-generation voltage conveyor (VCII), whose impedance at the Y port can be electronically varied using a control current (Icon), two capacitors, and one resistor are used. By changing the value of Icon, the impedance value at the Y port can be electronically varied; therefore, the value of ω0 can be tuned. This feature helps to reduce the number of passive components used. Interestingly, the LP and BP outputs are provided at the low-impedance Z port of the VCII, and there is no need for an extra voltage buffer for practical use. The circuit enjoys a simple realization consisting of only 24 MOS transistors. Simulation results using PSpice and 0.18 μm CMOS parameters are provided. The value of ω0 can be varied from 1.2 MHz to 1.7 MHz, while Icon varies from 0 to 50 µA, with a power consumption variation from 244 µW to 515 µW.

A Survey on Current-Mode Interfaces for Bio Signals and Sensors

“…An ideal second-generation voltage conveyor is nothing more than the dual active circuit block of the CCII [ 44 ]. This block is finding increasing applications as an alternative to the well-known voltage-mode circuit and the CCII itself [ 32 , 34 , 35 , 36 , 37 , 38 , 39 , 41 , 43 , 52 , 56 ]. As for the CCII, the information in a VCII is carried both by currents and voltages, but the VCII is equipped with both an input and an output voltage port.…”

“…The main current-mode analog blocks are the second-generation current conveyor (CCII) and its dual, the second-generation voltage conveyor (VCII). These blocks have been successfully applied to the realization of a variety of analog signal processing functions [ 30 , 31 , 32 , 33 , 34 , 35 , 36 , 37 , 38 , 39 , 40 , 41 , 42 , 43 , 44 , 45 , 46 , 47 , 48 , 49 , 50 , 51 , 52 ]. For example, in [ 31 ] a current-mode full-wave bridge rectifier has been developed; in [ 32 , 40 , 42 ] the realization of various filter functions using VCII is shown; and in [ 33 , 53 ] current-mode oscillators are described.…”

VCII based electronically tunable multi‐mode filter structure with fourth order low‐pass function for the HF band applications

“…Compared with the CCII based operations, some promising architectures are presented in different application areas. [17][18][19][20][21][22][23][24][25][26][27][28][29][30] In comparison to voltage mode counterparts of current mode filters, it can be said that current mode structures are more convenient for the HF operations based on the aforementioned requirements. There are different current mode filter architectures in the previous works for the low power consumption, high dynamic range, and facilitating mathematical operations.…”

“…Hence, they can be safely employed in current and voltage mode operations simultaneously. Compared with the CCII based operations, some promising architectures are presented in different application areas 17–30 …”

First‐order inverse filters: Implementations using a single voltage conveyor and potential applications

“…Second generation voltage conveyors (VCIIs) have been utilized for implementing conventional (i.e., non‐inverse) filters 10–16 . They are also used in Al‐Absi and Al‐Shahrani 17,18 for implementing first‐order voltage‐mode and current‐mode low pass and high pass inverse filters.…”