Open AccessDEVELOPMENT AND INVESTIGATION OF INPUT AMPLIFIER FOR THE OSCILOSCOPE
Author(s) -
Andžej Borel
Publication year - 2020
Publication title -
mokslas - lietuvos ateitis
Language(s) - English
Resource type - Journals
eISSN - 2029-2341
pISSN - 2029-2252
DOI - 10.3846/mla.2020.11420
Subject(s) - oscilloscope , amplifier , attenuator (electronics) , instrumentation amplifier , direct coupled amplifier , electrical engineering , operational amplifier , digital storage oscilloscope , current feedback operational amplifier , bandwidth (computing) , electronic engineering , computer science , analog front end , engineering , attenuation , physics , telecommunications , optics , voltage , cmos
Digital oscilloscope’s structure has analog signal acquisition circuit, which transforms signal’s amplitude to fit ADC dynamic range. This circuit is commonly called oscilloscope’s vertical or front-end amplifier. Difficulty in designing front-end amplifiers in GHz range largely affects higher frequency range oscilloscope’s price. This work is focused on designing a front-end amplifier using discrete and openly sold components. We propose a design for attenuator, buffer, variable gain circuits. Amplifier’s prototype is designed. Main characteristics of the amplifier were measured. Measured bandwidth is 3 GHz. Amplifier’s gain and attenuation can support vertical scale sensitivity range from 10 mV/div to 1 V/div. Step response distortion is under 10 %. SMD and PTH relay model attenuators were evaluated. In this paper we review oscilloscope’s front-end purpose and structure. We review amplifiers design and provide the results of experimental measurements.