Common centroid layout

A common centroid layout is a layout in which several electrical elements ( transistors , resistors , capacitors ) are arranged in an integrated circuit in such a way that interference remains as low as possible. For this purpose, the elements are split into several identical parts of the same size and arranged in such a way that the centroid of the various elements is at the same point (or at least as close to one another).

This arrangement minimizes disturbances by averaging such disturbances (e.g. temperature gradients , doping gradients ) between the elements and compensating for circuit parameters that are linearly dependent on them.

The arrangement is usually surrounded by so-called dummy devices without electrical function, which are intended to ensure the most uniform possible environmental conditions during manufacture. Since, especially when more than 2 elements with different sizes are to be arranged in this way, simple solutions for the arrangement are not always possible, further elements without function often have to be added in order to achieve a sufficiently good result.

A special sub-form is the quad layout .

literature

• R. Jacob Baker: CMOS: Circuit Design, Layout, and Simulation. 2nd edition, Wiley & Sons, 2007, ISBN 0470229411 .