Improved DC matching of CMOS circuits using Rotational Symmetry
T. Gabara, P.C. Metz · 2002
A layout technique called Rotational Symmetry has reduced the DC output voltage level variation of CMOS 100K ECL output buffers. Unlike the Common Centroid layout method, Rotational Symmetry compensates for process variations which cause voltage mismatches between distantly placed coupled buffers. This layout technique is also invariant to 90 degrees rotations.>