Battery-less active implantable devices are of interest because they offer longer life span and eliminate costly battery replacement surgical interventions. This is possible as a result of advances in inductive power transfer and development of power management circuits to maximize the overall power transfer and provide various voltage levels for multi-functional implantable devices. Rehabilitation therapy using optical stimulation of genetically modified peripheral neurons requires high current loads. Standard rectification topologies are inefficient and have associated voltage drops unsuited for miniaturized implants. This paper presents an integrated power management unit (PMU) for an optical-electrical stimulator to be used in the treatment of motor neurone disease. It includes a power-efficient regulating rectifier with a novel body biased high-speed comparator providing 3.3 V for the operation of the stimulator, a 3-stage latch-up charge pump with 12 V output for the input stage of the optical-electrical stimulator, and 1.8 V for digital control logic. The chip was fabricated in a $0.18 ~\mu \text{m}$ CMOS process. Measured results show that for a regulated output of 3.3 V delivering 30.3 mW power, the peak power conversion efficiency is 84.2% at 6.78 MHz inductive link tunable frequency reducing to 70.3% at 13.56 MHz. The charge pump with on chip capacitors has 90.9% measured voltage conversion efficiency.

中文翻译：

---

用于植入式光电刺激器的高效电源管理单元

无电池有源植入式设备很受关注，因为它们可以提供更长的使用寿命并消除昂贵的电池更换手术干预。这是可能的，因为感应电能传输的进步和电源管理电路的发展使整体电能传输最大化并为多功能植入式设备提供各种电压水平。使用光学刺激转基因周围神经元的康复治疗需要高电流负载。标准整流拓扑结构效率低下，并且相关电压降不适用于小型化植入物。本文介绍了用于治疗运动神经元疾病的光电刺激器的集成电源管理单元 (PMU)。它包括一个高能效调节整流器，带有一个新颖的体偏置高速比较器，为刺激器的运行提供 3.3 V 电压，一个具有 12 V 输出的 3 级闩锁电荷泵，用于光电刺激器的输入级和 1.8 V 用于数字控制逻辑。该芯片是在 $0.18 ~\mu\text{m}$CMOS工艺。测量结果表明，对于提供 30.3 mW 功率的 3.3 V 稳压输出，峰值功率转换效率在 6.78 MHz 电感链路可调频率时为 84.2%，在 13.56 MHz 时降至 70.3%。具有片上电容器的电荷泵具有 90.9% 的测量电压转换效率。