An Analysis of an ASK Demodulator With Dual Self-Biased Separated Voltages for Implantable Applications

• Published in: IEEE transactions on circuits and systems. II, Express briefs Vol. 71; no. 6; pp. 2986 - 2990
• Main Authors: Karimi, Mohammad Javad, Zhou, Yuxuan, Dehollain, Catherine, Schmid, Alexandre
• Format: Journal Article
• Language: English
• Published: New York IEEE 01.06.2024; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Amplitude shift keying; Amplitude shift keying (ASK); biomedical implants; data transmission; Demodulation; demodulator; Demodulators; Implants; Modulation; modulation index; Power consumption; Robustness; Schmitt triggers; Topology; Transistors
• ISSN: 1549-7747; 1558-3791
• DOI: 10.1109/TCSII.2024.3357212

A new structure of low-power demodulator named "separated-<inline-formula> <tex-math notation="LaTeX">V_{b} </tex-math></inline-formula>" amplitude shift keying (ASK) demodulator is proposed. The circuit is based on the switching behavior of the core digital shaper with different bias voltages, which improves its operation at low modulation indexes and reduces power consumption. This design does not require a comparator or Schmitt trigger, and only a few elements are needed which minimizes the chip area. The design is fabricated in the 0.18<inline-formula> <tex-math notation="LaTeX">\mu \text{m} </tex-math></inline-formula> CMOS process. The core chip area is 0.00144 mm2, and the power consumption is 45<inline-formula> <tex-math notation="LaTeX">\mu \text{W} </tex-math></inline-formula> at a 1.8V power supply. The data rate can be nearly 2.7 Megabits per second (Mbps) at 13.56 MHz.