A flexible biphasic pulse generating and accurate charge balancing stimulator with a 1μW neural recording amplifier

In this paper, we present a flexible biphasic pulse generating and accurate charge balancing stimulator with a 1μW neural recording amplifier. To achieve accurate charge balance, the stimulator is implemented using a dynamic current copying technique. It can generate a biphasic current pulse with an anodic scaling feature. To reduce power consumption, the recording amplifier is implemented to operate with 1V, while the stimulator works with 3V supply. They are implemented using a 65nm CMOS process. Simulation results show charge balance of less than 2% error in current pulses. The recording amplifier has an input referred noise of 4.5μVrms and passband from 1.5Hz to 5KHz with the power consumption of 1μW.