A Single-Input Multi-Output Resonant Regulating Rectifier Generating Three Outputs in a Half Cycle for Wirelessly Powered Biomedical Devices

This paper introduces single-input multi-output (SIMO) resonant regulating rectifier (R³) designed to produce three regulated outputs in a half cycle without low drop-out (LDO) regulators. Utilizing distributed multi-phase control allows for the regulation of three outputs in a half cycle, leading to increased power delivered to the load (PDL), reduced output ripple, and a higher number of outputs. Additionally, the adoption of negative threshold gate driver (NTGD) and a hybrid high/low comparator (HCMP) enhances the output voltage regulation range and power conversion efficiency (PCE). To ensure the safe control of three distinct outputs in a half cycle, all three outputs are equipped with end protection techniques. Moreover, for a secure start-up of the secondary outputs, the proposed pre-biasing technique in the pulse width modulation (PWM) controller is implemented. The 1.54-mm $^{2}~0.25$ - $\mu $ m CMOS SIMO R³ demonstrates the capability to generate three regulated outputs, with a maximum primary voltage and minimum secondary voltage difference of up to 3.5 V. Furthermore, a PCE of 90.82% is achieved with a total load power of 84.6 mW. These advancements position the SIMO R³, especially with dynamic voltage scaling (DVS) stimulation, as a promising solution for efficient use in retinal prostheses.