Abstract |
This paper deals with the development of bio-implanted micro-system with
low-power and high data rate based on amplitude shift keying (ASK) modulation
technique to stimulate nerves and muscles. The modified system is operated by a
low-frequency band 13.56MHz according to the industrial-scientific-medical (ISM)
bands to avoid the biological tissue damage. The data rate on the demodulator
side is from 1Mb/s and up to 1.5Mb/s depending of generating binary signal
(TBIT) 1 µs or 0.5 µs) with modulation index of 13% and modulation rate 7.3%, 9%
and 11%, respectively. The proposed inductive coupling link achieves 73% of link
efficiency. The modified rectifier with self-threshold voltage cancellation
techniques and voltage regulator without thermal protection circuit and without
passive elements occupies small area that is modified to generate adequate and
stable DC voltages of1.8V. A new ASK demodulator structure based on two
comparators is developed to extract a synchronized demodulated signal with
minimum error. Thereby no need for clock recovery circuit and delay-locked loops
(DLL) circuits for data synchronization at 1Mb/s and1.250Mb/s of speed. The
system designed using OrCAD Pspice 16.2 is based on 0.35 µm technologies. |