Journal of Zhejiang University SCIENCE A
(Monthly)

2006   Vol. 7   No. 6   p. 1056-1060

A wideband frequency-shift keying demodulator for wireless neural stimulation microsystems

DONG Mian^†1, ZHANG Chun², MAI Song-ping¹, WANG Zhi-hua², LI Dong-mei¹

(¹Department of Electronic Engineering, Tsinghua University, Beijing 100084, China)
(²Institute of Microelectronics, Tsinghua University, Beijing 100084, China)
^†E-mail: dongmian99@mails.tsinghua.edu.cn
Received Sept. 12, 2005 revision accepted Mar. 29, 2006

Abstract: This paper presents a wideband frequency-shift keying (FSK) demodulator suitable for a digital data transmission chain of wireless neural stimulation microsystems such as cochlear implants and retinal prostheses. The demodulator circuit derives a constant frequency clock directly from an FSK carrier, and uses this clock to sample the data bits. The circuit occupies 0.03 mm² using a 0.6 μm, 2M/2P, standard CMOS process, and consumes 0.25 mW at 5 V. This circuit was experimentally tested at transmission speed of up to 2.5 Mbps while receiving a 5~10 MHz FSK carrier signal in a cochlear implant system.

Key words: Biomedical implants, CMOS, Demodulator, Frequency-shift keying (FSK), Cochlear implant
doi:10.1631/jzus.2006.A1056             CLC number: TN76

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