Single Supply PWM Fully Implantable Cochlear Implant Interface Circuit With Active Charge Balancing

Low powered fully implantable cochlear implants (FICIs) untangle the aesthetic concerns and battery replacement problems of conventional implants. However, reported FICIs lack proper charge balancing require multiple external supplies to operate. In this work, a complete low power FICI interface circuit is designed that operates with single supply uses short-pulse-injection method for balancing. The system takes input from multi-channel piezoelectric transducers stimulates auditory neurons pulse width modulated (PWM) output currents. By utilizing modulation technique continuous interleaved sampling (CIS) sound processing strategy, time gap formed between two consecutive channels. Then, used operation. Overall consumption decreased by clocked gated subthreshold amplifier rectifier design. Furthermore, efficient design analog digital converter (ADC) enhances reduction. tested an in-vitro test setup it channel electrode 50 dB dynamic range while consuming 695 μW 1.8 V supply. implemented can safely stimulate more than 18 days (with 16-hour daily operation) 200 mWh without recharging. short balance current pulses keep voltage difference after stimulation within ±100 mV range, which ensures residual not hazardous neurons.