Z Copy‐Controlled Gain‐Current Differencing Buffered Amplifier and its applications

Abstract

The Z Copy‐Controlled Gain‐Current Differencing Buffered Amplifier (ZC‐CG‐CDBA) is introduced in the paper. In addition to the well‐known CDBA, the input Current Differencing Unit (CDU) is modified and completed by special circuits. Analogously to the conventional CDBA, the z terminal is internally connected to the input of voltage buffer. The current gain from the difference input p, n to the output z can be controlled electronically or by an external device. In addition, an independent high‐impedance output zc is available, providing difference current Ip−In. In the paper, the extension of application range of the ZC‐CG‐CDBA compared with the conventional CDBA is referred to. The novel circuit element is assembled from commercial integrated circuits and its principle is verified experimentally on a universal second‐order filter. Copyright © 2010 John Wiley & Sons, Ltd.

An Additional Approach to Model Current Followers and Amplifiers with Electronically Controllable Parameters from Commercially Available ICs

“…Alzaher et al [14,15] and Koton et al [16] utilized digital control of current gain in their active elements and applications. Current gain control received important attention also in more complicated active elements formed by basic functional components, for example current differencing buffed amplifier (CDBA) presented by Biolek et al in [17] and [18], programmable current amplifier (PCA) introduced by Herencsar et al [19], current gain controlled current conveyor transconductance amplifier (CGCCCTA) discussed in [20], etc.…”

Study of Small-signal Model of Simple CMOS Amplifier with Instability Compensation of Positive Feedback Loop

“…)) are compared with expected magnitude responses from AC model presented later in Fig.14. and with transfer function (8). Potential issues with stability are typical for lower gains.…”

“…It is clearly seen that E g has impact on pole quality and frequency and decreases with higher gains. Both obtained transfers (13) and (16) are compared with (8) and "uncompensated" transfer (5) in Fig.13. for C m = 0 pF and three different gains.…”

“…We can discuss methods like transconductance (g m ) control [1], [2] intrinsic current input resistance control (R x ) [1], [3] current gain control (B) [4][5][6][7][8], voltage gain control (A) [9], and their combinations [10][11][12][13][14].…”

First–Order Transfer Sections with Reconnection–Less Electronically Reconfigurable High–Pass, All–Pass and Direct Transfer Character

“…Active elements combining current inverter and transconductance amplifier have been already investigated precisely. For example current inverter transconductance amplifier (CITA) and its modifications (using so-called Z-copy technique [20]) were reported in recent literature [21]. Active elements presented in previously discussed work have only one possibility of control by electronically adjustable transconductance.…”