New CMOS current-mode amplitude shift keying demodulator (ASKD) dedicated for implantable electronic devices

We propose in this paper a new CMOS integrated amplitude shift-keying (ASK) demodulator dedicated for implantable electronic device (IED) systems. ASK modulation is commonly used in the wireless data transmission systems of IEDs. The proposed ASK demodulator (ASKD) is used to extract digital data from two-level ASK modulated current signal. The ASKD allows to detect current levels with very small modulation depth which is defined as the difference between the two allowable ASK amplitude levels. The design is not complex and it is less sensitive to process variation. The circuit is implemented with 0.18 μm, 1.8 V CMOS technology and currently it is under fabrication. Preliminary post-layout simulation results allow to prove the proposed concept for an input signal of 250 KHz at current amplitude varying between 4 and 4.5 μA.