Patent ID: 7977762

Claim:
An integrated circuit (IC) comprising: a central area of the IC that is partitioned into a first section containing at least one digital circuit and a second section containing at least one analog circuit; a guard strip that is within the central area and that is positioned between the digital circuit and the analog circuit, where the guard strip includes at least one shield section, where each particular shield section includes an n-type well and a p-tap, and where the position, within the particular shield section, of the n-type well is closer to the digital circuit than is the position, within the particular shield section, of the p-tap, further where the guard strip includes N shield sections, N being two or more; the shield sections are numbered from 1 to N, with shield section number 1 being the shield section that is closest to the digital circuit, shield section number 2 being next closest to the digital circuit, and so on through shield section number N which is the shield section that is closest to the analog circuit; and the n-type well in the shield section number 1 is wider than the n-well in the shield section number 2 , and so on through the shield section number N which has the narrowest n-well among all of the shield sections.