CMOS ASK system modulation dedicated to cochlear prosthesis

In this paper, we propose a modulator and a demodulator which are suitable for a digital data transmission chain for cochlear prostheses. This ´ASK´ (amplitude shift keying) type of modulation system would be integrated later with CMOS technology. Such integration involves the external part (modulator) as well as in the internal circuit of the cochlear implant (demodulator). Transmitted digital data would be modulated by the external part with a carrier frequency of 20 MHz. They would be transmitted then in ´RF´ to the internal part of the prosthesis through an inductive link at 1 Kbits/s data rate. The conception has been achieved completely in CMOS in order to minimize the energy consumption as well as the occupation area in the desired integrated circuit. The architecture presented in this article has been validated by simulations on the PSPICE software tool using a 0.35μm CMOS technology.