In electronics terms, the recommended maximum fanout of a device is the maximum number of input loads a given circuit element's output can drive without deterioration in performance. The load seen by a given circuit element's output driver is a combination of the input loads of the elements it drives and the wireload of the nets connecting these inputs to the output driver.

Normally, a component's fanout is expressed in terms of a number of "standard load" units. The value of this "standard load" varies from one technology to the next, and is representative of the input load of a typical device from a given logic family. The larger a component's output driver, the higher its maximum fanout will be.

A high fanout net may need to be buffered in order that signals on the net are 'clean' enough to be used by the device inputs it drives.

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