Open AccessHigh‐efficiency self‐powered oscillator for capacitive neural stimulation
Author(s) -
Hong G.,
Han G.
Publication year - 2018
Publication title -
electronics letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.375
H-Index - 146
ISSN - 1350-911X
DOI - 10.1049/el.2017.4322
Subject(s) - relaxation oscillator , power (physics) , electrical engineering , capacitor , capacitive sensing , cmos , electronic circuit , signal (programming language) , electronic engineering , pulse (music) , voltage , engineering , computer science , physics , voltage controlled oscillator , quantum mechanics , programming language
Implantable neural stimulation devices have drawn attention for various clinical purposes. Capacitor‐coupled stimulation inherently maintains charge‐balance, allowing the use of less complex pulse‐generating circuits. This Letter proposes a self‐powered relaxation oscillator, which allows direct charge transfer from the energy harvester to the capacitive stimulation electrode. As the proposed circuit does not require power supply to operate the oscillator itself, it achieves high power efficiency by eliminating wasted current from the power supply to the ground. A prototype of the proposed oscillator was fabricated with a 0.35 μm standard CMOS process. The prototype chip demonstrates power efficiency of up to 94.1% at 520 Hz for 1.4 V signal swing.