Characterisation of substrate noise in FLASH A/D converters

A method for modelling electromagnetically coupled substrate noise in mixed signal integrated circuits was developed. This method was then used to characterise the substrate noise issues in FLASH analogue to digital (A/D) converters. The model was also used to study the addition of the P⁺ guards around the input devices of the comparators in order to assess their effectiveness in reducing the substrate noise. Finally, the effect of variations in the package´s bond wire inductances in the net injected current noise was modelled.