A self tuning system for on-die terminators in current mode off-chip signaling

A system for self tuning of on-die terminators in current mode off-chip signaling is presented. The proposed method is based on an algorithm that uses the sign of the impedance matching error and the sign of the coupling branch current to perform the self tuning operation. The circuit implementation of the system is described and computer simulations at the transistor level are presented for process, temperature and load impedance variations.