On the realization of current transfer function using voltage amplifiers

Abstract

Current transfer function is a feature of current‐mode filters. Current‐mode filters have so far been realized principally using current amplifiers and current conveyors. Some current‐mode filter architecture using operational amplifiers have also been reported. In this article it is shown that by using the principles of transposed network and nullor model for the active device, a current transfer function can be realized in a very simple way using a voltage amplifier, i.e. operational amplifier (OA). The key concept is the knowledge that each ideal (i.e. infinite gain) controlled source is exactly equivalent to a nullor. Thus, a voltage‐mode filter implemented using an ideal three terminal (output, input and ground) OA can be very easily converted to a current‐mode filter using the same OA. The principle has been illustrated by considering single‐OA‐ and multi‐OA‐based second‐order voltage‐mode filters. SPICE simulation results are provided to validate the theoretical concept. Copyright © 2006 John Wiley & Sons, Ltd.

Using MOS current dividers for linearization of programmable gain amplifiers

“…Furthermore, the application of this technique to current mode configurations is straightforward and could be realized to take advantage of current mode operation [19].…”

Universal resistorless current‐mode filters employing CCCIIs

“…Much research has been devoted to the realization of current-mode (CM) filters [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17] employing various active devices because of their versatility and convenience for practical usages in many areas, such as communication systems and signal processing. Thus, a number of CM filter designs are proposed in the literature employing operational amplifiers (OAs) [1], current conveyors (CCs) 740 E. YUCE, A. KIRCAY AND S. TOKAT [2][3][4][5][6][7][8] and second-generation current-controlled conveyors (CCCIIs) [9][10][11][12][13][14][15][16][17].…”

“…Thus, a number of CM filter designs are proposed in the literature employing operational amplifiers (OAs) [1], current conveyors (CCs) 740 E. YUCE, A. KIRCAY AND S. TOKAT [2][3][4][5][6][7][8] and second-generation current-controlled conveyors (CCCIIs) [9][10][11][12][13][14][15][16][17]. On the other hand, it is stated in [18,19] that CM operations have better properties, such as greater linearity, lower power consumption, wider bandwidth and larger dynamic range than their voltage-mode (VM) counterparts, for example, OAs.…”

Current-Mode Filters Using Voltage Amplifiers

“…In a recent article [7], the authors have briefly reported on this concept. In this article, we shall elaborate on the application of the principles of nullor and transposed networks for the realization of a CM filter from a given VM realization.…”