Analogno-digitalna pretvorba napetosti in toka visokofrekvenčnih elektroporacijskih pulzov ter galvanska izolacija

Košir, Lea Margareta (author), Reberšek, Matej (mentor)

V diplomski nalogi je obravnavana zasnova in izvedba tiskanega vezja za analogno-digitalno pretvorbo elektroporacijskih pulzov z galvansko ločitvijo. Elektroporacijski pulzi predstavljajo zelo kratke in visokonapetostne signale, katerih zajem zahteva hitro, natančno in varno merilno vezje. Osrednji problem, ki ga naloga obravnava, je, kako zanesljivo pretvoriti takšne pulze v digitalno obliko, hkrati pa zagotoviti zaščito merilnega sistema in uporabnika s primerno izvedeno galvansko ločitvijo. Za rešitev problema je bila izvedena analiza obstoječih raziskav in seminarjev, na podlagi katere je bila pripravljena kosovnica ter izbor primernih integriranih vezij. V okolju Altium Designer so bile najprej izdelane tri vezalne sheme – za meritev toka, meritev napetosti in napajalni del. Pri načrtovanju tiskanega vezja je bila določena velikost ploščice (110 × 95 mm) in izvedena postavitev komponent glede na funkcionalne sklope. Posebno pozornost je zahtevala izvedba galvanske ločitve, kjer je bilo določeno področje izolacijske razdalje in izrez v tiskanini za zagotavljanje zadostne plazilne razdalje. Vezje je bilo izvedeno kot dvoplastna zasnova, pri čemer je zgornja plast namenjena večini signalnih povezav, spodnja plast pa v večji meri služi kot skupna ozemljitvena ravnina (ground plane). V središču vezja je uporabljen 16-bitni analogno-digitalni pretvornik LTC2387-16, ki omogoča hiter zajem z vzorčno frekvenco do 15 Msps. Za galvansko ločitev digitalnega dela so bili uporabljeni izolatorji serije ADN4620/4621, za napajanje pa izolirani DC/DC pretvorniki tipa MEJ1S0505SC, kar omogoča ločeno napajanje visokonapetostne in nizkonapetostne strani. Rezultat naloge je delujoča vezalna shema in postavitev tiskanega vezja, ki ustreza varnostnim in funkcionalnim zahtevam zajema elektroporacijskih pulzov. Glavni zaključek naloge je, da je mogoče z ustrezno izbiro komponent, natančno postavitvijo in spoštovanjem pravil o izolaciji izdelati zanesljiv merilni vmesnik za visokonapetostne impulze, ki omogoča varno in kakovostno digitalizacijo signala za nadaljnjo obdelavo.

• Language: Slovenian
• Keywords: analogno-digitalna pretvorba, galvanska ločitev, tiskano vezje
• Work type: Bachelor thesis/paper
• Organization: FE - Faculty of Electrical Engineering
• Year: 2025
• PID: 20.500.12556/RUL-172832
• Publication date in RUL: 11.09.2025

Secondary language

• Language: English
• Title: Analog-to-digital voltage and current conversion of high-frequency electroporation pulses and galvanic isolation

Abstract

This thesis presents the design and implementation of a printed circuit board for the analog-to-digital conversion of electroporation pulses with galvanic isolation. Electroporation pulses are short, high-voltage signals that require fast, precise, and safe acquisition circuits. The main problem addressed in this work is how to reliably digitize such pulses while ensuring the protection of both the measurement system and the user through proper galvanic isolation. To address this problem, an analysis of existing research and seminar work was carried out, followed by the preparation of a bill of materials and the selection of suitable integrated circuits. Three schematics were created in Altium Designer: for current measurement, voltage measurement, and power supply. In the PCB design phase, the board size was set to 110 × 95 mm, and components were arranged according to functional blocks. Particular attention was paid to galvanic isolation, which required the definition of keep-out zones, insulation distances, and a board cutout to achieve the required creepage distance. The PCB was designed as a two-layer board, with the top layer mainly used for signal routing and the bottom layer serving primarily as a ground plane. At the core of the circuit is the 16-bit ADC LTC2387-16, capable of sampling rates up to 15 Msps. Digital isolation was implemented using ADN4620/4621 isolators, while power isolation was achieved with MEJ1S0505SC DC/DC converters, ensuring separate supplies for the high-voltage and low-voltage domains. The outcome of this work is a complete schematic and PCB layout that meets both safety and functional requirements for the acquisition of electroporation pulses. The main conclusion is that with proper component selection, careful layout, and adherence to isolation rules, a reliable measurement interface for high-voltage pulses can be realized, enabling safe and accurate signal digitization for further processing.

• Keywords: analog-to-digital conversion, galvanic isolation, printed circuit board