This work presents a fully discrete, low cost digital isolator requiring no specialized ICs and implemented entirely with general purpose transistors and a two layer PCB embedded air core transformer. The design avoids vendor lock in and long term component obsolescence risks, while providing >1 kV isolation, ~200 ns propagation delay, and validated NRZ data rates of 1 Mbps. A modified dual oscillator architecture enables inherent hardware lockout suitable for half bridge gate driver applications. Measured performance and PCB layout guidelines are provided.
Cite
@article{arxiv.2603.24096,
title = {A Low Cost Discrete Digital Isolator Circuit},
author = {Thomas Conway},
journal= {arXiv preprint arXiv:2603.24096},
year = {2026}
}