A Neurostimulator with Differential Charge Packet Injection Charge Balancing

A neurostimulator system is presented in this paper to provide a configurable current stimulus patterns for Deep Brain Stimulation (DBS). The stimulation system utilizes eight standard H-bridge current stimulators, each capable of generating a stimulation current of up to ±2.55mA. A novel charge recovery circuit of differential charge packet injection (DCPI) is proposed to achieve high-precision charge recovery. The neurostimulator is implemented in a 0.18μm BCD process. DCPI technique is used to reduce the residual voltage on the electrode-electrolyte interface during the inter-pulse time interval, which achieve 3 mV charge balancing precision with less sequential logic.