Modification of Current Follower/Amplifier with Controllable Intrinsic Resistance

This contribution presents a modification of behavioral model of a current follower/amplifier with electronically controllable current input resistance. This modification focuses on the increase of available outputs of the device and electronically controlled gain of each output separately. Moreover, the modified concepts are then adjusted in manner of possibility of their usage in circuits which work with differential signals. The PSpice simulations serve for verification of proposed solutions. Introduced universal current-mode filter includes proposed behavioral models in order to verify presented features in application.

I. Introduction

An electronic control of multiple parameters within various applications (pole frequency, quality factor, the level of gain in pass-band/stop-band region in case of frequency filters, oscillation condition, frequency of oscillations, amplitude of oscillations in oscillators, etc.) belongs to still sought features in current state-of-the-art. Thus, the active elements implementing control of multiple parameters (input/output impedance, gain) are in awareness and in attention of many scientific teams.