A 83 peak efficiency 1.65 V to 11.4V dynamic voltage scaling supply for electrical stimulation applications in standard 0.18μm CMOS process

摘要

In this paper, we present a dynamic voltage scaling supply (DVSS) for electrical stimulation applications. The core architecture of the proposed DVSS is based on a 7x series-parallel charge pump structure. It converts 1.65V DC input into N × 1.65V DC output in which the number of N can be dynamically scaled from 1 to 7. The DVSS circuit consumes a static power of 20μW and achieves a peak efficiency of 83.3% under a constant current load of 500μA at output voltage of 3 × 1.65V. The DVSS circuit has a fast response time of 146ns when switching from standby to the maximum 11.4V output. It has an intrinsic energy recycling mechanism to effectively reduce the energy wastage when switching DVSS from active to standby state. The DVSS circuit is designed and implemented in a standard 0.18μm CMOS process without high-voltage (HV) transistor option, which saves mask cost and provides possibility for HV stimulation system to be designed and integrated in more advanced technology node.