Abstract
This paper presents a fully-integrated current-controlled stimulator that is powered directly from on-chip coil antenna and achieves adiabatic energy-replenishing operation without any bulky external components. Adiabatic supply voltages, which can reach a differential range of up to 7.2 V, are directly generated from an on-chip 190-MHz resonant LC tank via a self-cascading/folding rectifier network, bypassing the losses that would otherwise be introduced by the 0.8 V system supply-generating rectifier and regulator. The stimulator occupies 0.22 mm2 in a 180 nm silicon-on-insulator process and produces differential currents up to 145 \muA. Using a charge replenishing scheme, the stimulator redirects the charges accumulated across the electrodes to the system power supplies for 63.1% of stimulation energy recycling. To benchmark the efficiency of stimulation, a figure of merit termed the stimulator efficiency factor (SEF) is introduced. The adiabatic power rails and energy replenishment scheme enabled our stimulator to achieve an SEF of 6.0.
Original language | English (US) |
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Article number | 8537908 |
Pages (from-to) | 191-202 |
Number of pages | 12 |
Journal | IEEE Transactions on Biomedical Circuits and Systems |
Volume | 13 |
Issue number | 1 |
DOIs | |
State | Published - Feb 2019 |
Keywords
- Adiabatic stimulation
- brain initiative
- electrocorticography
- neural stimulation
- neural technology
- neuromodulation
ASJC Scopus subject areas
- Biomedical Engineering
- Electrical and Electronic Engineering