Comparative Study of Two Capacitive Isolation Information Transmission Systems

In this paper, a comparative study of two capacitive isolation information transmission systems is conducted. Previously two systems designed for an AC-switch driving were proposed. Thanks to capacitive isolation, the proposed systems are compatible not only with CMOS technology but also with strong magnetic field environment such as MRI equipment. Both systems share the same modulator but differ in demodulator: one uses an inverter-based envelope detector and the other uses a current-source-based envelope detector. The comparison is based on Monte-Carlo (MC) simulation in purpose to compare the robustness in terms of carrier frequency stability, power consumption and signal delay between the two systems. To enhance the circuit robustness against technological dispersions, improvement has also been brought to the initial systems. Both systems are designed in CMOS HV $0.35 \mu \mathrm{~m}$ technology under 3.3 V supplies and MC simulations are given.