A reconfigurable 16-channel HV stimulator ASIC for Spinal Cord Stimulation systems

A 16-channel stimulation waveform generator ASIC using high voltage CMOS technology to generate high voltage stimulation signals for Spinal Cord Stimulation (SCS) systems is presented in this study. To enlarge the voltage swing on high-impedance electrodes, the output stage of the proposed for the SCS systems is implemented on silicon using a 0.25 μm high-voltage (60 V) devices. Particularly, a charge pump composed of 5 cascaded voltage doublers is used to boost the core voltage (2.5 V) to higher than 10 V required by the SCS systems to execute electrical stimulation therapy [1]. A total of 16 stimulation waveform generators are included to drive 16 sets of electrodes, where each generator is composed of an HV operational amplifier and an HV analog switch. Compared with existing commercial products, the proposed SCS system attains better flexibility to meet the spinal cord stimulation high voltage demand in addition to the reduction of cost and PCB size.