Substrate Noise Coupling in Mixed-Signal ASICs

Although most functions in such integrated systems are implemented with digital or digital signal processing circuitry, the analogue circuits needed at the interface between the electronic system and the continuous-valued outside world are also being integrated on the same die for reasons of cost and performance. Unfortunately, the integration of both analogue and RF circuits and digital circuits on the same die not only offers many benefits, but also creates some technical difficulties. Since the analogue circuits exploit the low-level physics of the fabrication process, they remain difficult and costly to design, but they are also vulnerable to any kind of noise or crosstalk signals.