High speed I/O buffer design for MCM

It is well known that a bare die packaged in a MCM module will be exposed to a better electrical environment. Besides speed improvement, due to the lighter loading effects, chip power consumption can be reduced if conventional CMOS I/O buffers are replaced by some smaller and fancier ones, in which ESD protection mechanisms are removed. In this approach, chip designer must be involved in the task for devising those target chips to be packed into a MCM. In this paper, three types of differential CMOS I/O buffers especially for MCM will be discussed and their performances compared. In addition to the differential types, a new sets of I/O buffers, switchable MCM CMOS I/Os, meeting both MCM and PWB requirements, will also be investigated. And finally, the simulation and experiment results will follow.