Design Of Wireless Data And Clock Recovery Circuity In Retinal Prosthesis

According to the official statistics by the WHO,in 2010 the number of people visually impaired was estimated to be 285 million,of whom 39million were blind.With the improvement of biological technology and medical technology,implantable medical devices have been developed fast,and the retinal prosthesis is researched to improve the visually impaired situation.Retinal prosthesis converts the optical signal captured by the camera to electrical signal,and uses Functional Electrical Stimulation to stimulate corresponding nerve cells to rebuild the visual path and finally restore vision.In the retinal prosthesis,compared with using wire transmission to transmit data and power,it is more comfortable and safe to use wireless data and power transmission.This thesis is to design a wireless data and clock recovery circuitry for the retinal prosthesis chip.Literature surveys have been done on the methods to recover data and clock in retinal prosthesis,and the architecture of the system and the design parameters of the modules are discussed and determined.After that the design of every sub-module of the wireless data and clock recovery module is introduced,including ASK demodulator,carrier clock recovery circuit and Manchester decoder.All the circuits are verified by the analog design tools and the layout design is also done.The chip is designed with the process of XFAB 0.35μm.The ASK demodulator and carrier clock recovery circuit have been taped out,and the Manchester decoder is verified on the FPGA.According to the post-layout simulation results,the wireless data and clock recovery circuitry is able to demodulate ASK signal whose input amplitude variation is between 0.05V and 6V and modulation index variation is between 1.1%and 100%.And it can recover carrier clock of 13.56MHz.The core area of the entire circuitry is 0.027mm~2 and the power dissipation is 180.6uW.