Methodology to determine dominant noise source in a system-on-chip based implantable device

In a mixed-signal environment, a challenging issue during the design process of analog circuits is the evaluation of the dominant noise source. A fair comparison of intrinsic (device) noise with induced (switching) noise is highly important to enhance design constraints such as input sensitivity and signal-to-noise ratio. A methodology and analysis flow are proposed to quantify and compare input-referred device noise with input-referred switching noise in a system-on-chip based implantable device, where input sensitivity is a critical design constraint. It is demonstrated that switching noise due to substrate coupling is approximately 30 dB higher than device noise in the frequency range of interest.