A Fully-Integrated Many-Electrodes Pulsed-Voltage Control Architecture for Arbitrary-Waveform Neural Stimulation With High Energy Efficiency
Year: 2025
Type: article
Abstract: Deeply implantable neural stimulation calls for architectural solutions that are small, efficient and flexible, and that can stimulate many electrodes. To this end, this paper proposes the use of a pulsed (chopped) voltage stimulator, implemented using a low-complexity switch network with fully adaptive real-time control. The fully-integrated control architecture guarantees current waveform reconstruction and charge balancing by continuously monitoring the charge delivered to the electrode, thus offering robustness towards power-supply voltage and electrode impedance variations. The architecture has a high energy efficiency across the entire output operating range. The output waveform is generated in charge samples (slices) of controlled amount; by controlling these slices properly, the desired arbitrary stimulation waveform is constructed. A voltage monitoring circuit is used to apply active charge balancing; the duration of the balancing phase is adjusted by varying the number of charge samples. The feasibility of the architecture is demonstrated with a chip prototype manufactured in a180 nm,1.8 V/5 VCMOS process, and has an area of only0.027 mm2per non-multiplexed stimulator channel. Across the entire output operating range, the experimental validation of the prototype demonstrates a source energy efficiency that is up to 35 % better than previously published implementations. The results show that this architecture is a viable solution for next-generation systems for neuromodulation and closed-loop neural monitoring.
Institution: KU Leuven
Language: English
Subfield: Biomedical Engineering
Field: Engineering
Domain: Physical Sciences
Open Access status: green
Funder: Fonds Wetenschappelijk Onderzoek
OpenAlex ID: W4409257358