IEEE Trans Biomed Circuits Syst. 2019 Feb;13(1):191-202. doi: 10.1109/TBCAS.2018.2881800. Epub 2018 Nov 16.
This paper presents a fully-integrated current-controlled stimulator that is powered directly from on-chip coil antenna and achieves adiabatic energy-replenishing operation without any bulky external components. Adiabatic supply voltages, which can reach a differential range of up to 7.2 V, are directly generated from an on-chip 190-MHz resonant LC tank via a self-cascading/folding rectifier network, bypassing the losses that would otherwise be introduced by the 0.8 V system supply-generating rectifier and regulator. The stimulator occupies 0.22 mm in a 180 nm silicon-on-insulator process and produces differential currents up to 145 μA. Using a charge replenishing scheme, the stimulator redirects the charges accumulated across the electrodes to the system power supplies for 63.1% of stimulation energy recycling. To benchmark the efficiency of stimulation, a figure of merit termed the stimulator efficiency factor (SEF) is introduced. The adiabatic power rails and energy replenishment scheme enabled our stimulator to achieve an SEF of 6.0.
本文提出了一种完全集成的电流控制型刺激器，它直接由片上线圈天线供电，并通过自级联/折叠整流器网络从片上 190MHz 谐振 LC 槽中直接产生可达 7.2V 差分范围的绝热供电电压，从而绕过了由 0.8V 系统供电生成整流器和稳压器引入的损耗。该刺激器在 180nm 硅绝缘体工艺中占据 0.22mm 面积，可产生高达 145μA 的差分电流。使用电荷补充方案，刺激器将电极上积累的电荷重定向到系统电源，实现 63.1%的刺激能量回收。为了基准化刺激效率，引入了一个称为刺激器效率因子（SEF）的衡量标准。绝热功率轨和能量补充方案使我们的刺激器达到了 6.0 的 SEF。
