An Efficient-Rectification Power Management Module for Brain Computer Interface Chip

Xin Zhang
Master, School of Microelectronics, Shanghai University, Shanghai, China, 200000
Dr. Jiahao Cheong
MTRIX Technology, Shanghai, China, 200000
Cheng Liu
Professor, School of Microelectronics, Shanghai University, Shanghai, China, 200000

Abstract:

This paper discusses the design of the rectifier, a key part of the power management module in Brain-Computer Interface (BCI) technology. Due to the many problems of traditional lithium battery power supply, wireless power supply technology, in particular magnetic coupled resonant wireless power transfer (MCR-WPT) technology, provides a new solution for the power supply of BCI chip. The paper first analyzes the importance of rectifiers in the power management module of BCI chips. Subsequently, four different rectifier circuit structures are introduced, and by comparing their performances, the rectifier design configuration with full-bridge rectifier MOSFET (Metal Oxide Semiconductor Field Effect Transistor) architecture and using MOSFET with bulk regulation is selected. This configuration has a high rectifier efficiency and voltage transfer ratio, and a lower output voltage ripple. Then, this paper indicates the operation principles of the rectifier, and explains how the rectifier converts the input sinusoidal signal into a stable DC voltage. During the design, this paper pays the most attention on several key parameters, including the value of output voltage, transfer voltage ratio, power supply rejection ratio (PSRR), and rectifier efficiency. In the discuss of the rectifier design, the optimal parameters of the MOS are determined by simulations and calculations, which allows the rectifier to strike a balance between performance and layout area. Finally, this paper illustrates the waveforms of the final version of the rectifier by virtuoso, which means that the rectifier can effectively convert the sinusoidal signal into a stable DC voltage with a value of 2.1 V, which meets the requirements of the BCI chip, and this rectifier has a transfer voltage ratio of 0.86, a PSRR of 52.42 dB and a rectifier efficiency of 74.37%. The proposed design of rectifier in this paper provides an efficient and reliable configuration for the power management module of BCI chips, which could promote the development of BCI technology.