Hsu, Wen-YangSchmid, Alexandre2017-07-182017-07-182017-07-18201710.1109/TBCAS.2017.2694144https://infoscience.epfl.ch/handle/20.500.14299/139346WOS:000406406900014Safety and energy efficiency are two major concerns for implantable neural stimulators. This paper presents a novel high-frequency, switched capacitor (HFSC) stimulation and active charge balancing scheme, which achieves high energy efficiency and well-controlled stimulation charge in the presence of large electrode impedance variations. Furthermore, the HFSC can be implemented in a compact size without any external component to simultaneously enable multichannel stimulation by deploying multiple stimulators. The theoretical analysis shows significant benefits over the constant-current and voltage-mode stimulation methods. The proposed solution was fabricated using a 0.18 μm high-voltage technology, and occupies only 0.035 mm2 for a single stimulator. The measurement result shows 50% peak energy efficiency and confirms the effectiveness of active charge balancing to prevent the electrode dissolution.Active charge balancingenergy efficientimplantable biomedical devicesNeural stimulatorswitched-capacitortext::journal::journal article::research article