Digital Active Substrate Noise Canceller
With the development of CMOS process, the number of transistors can be placed on one unit of area is increasing rapidly, enabling us to integrate many analog and digital components into a single chip. However, in high transistor density chip, substrate noise may become problem, degrading circuit’s performance. Therefore, we propose a digital active substrate noise canceller which can suppress substrate noise by injecting cancelling signal with inverse phase into the substrate. The amplitude and waveform of the cancelling signal can be controlled to ensure higher effectiveness. Because this noise canceller is digitally configurable, it can be easily controlled and suitable for automatic operation control in system LSI.