Automatic On-Die Impedance Matching in Current Mode Off-Chip Signaling

摘要

A system for on-die automatic impedance matching in current mode off-chip signaling is described. In order to perform the automatic matching operation, an algorithm that integrates the sign of the impedance matching error and the sign of the coupling branch current is implemented. An advantage of the proposed system is that it works without interfering with the driver operation. The transistor level circuit implementation of the system is described and computational simulations with post layout extractions are presented. Also experimental results are shown in order to prove the performance of the system.