Ruprecht-Karls-Universität Heidelberg


Design of a T-Coil Termination and an Electrostatic Discharge Structure in 28nm

Project Report by Stefan Kosnac

Abstract:

I/O-terminals of microchips need to be able to carry signals in the order of 10 GHz and must not disturb them to much. Additionally, terminals must be protected against electrostatic discharge (ESD) events. They occur when humans or machines discharge between two terminals or when the device built up charge itself. All these events involve high voltages and currents, but low overall energy. Nevertheless, transistor gates are sensitive to high static voltages. In current technologies, a few volts are enough to destroy a gate oxide. In this work, a T-coil termination is implemented to avoid signal degradation. Furthermore, ESD structures are applied to provide electrostatic protection of the power- and I/O-pins. The schematic level results in terms of return loss are quite good, but the common signal reflection still needs some inprovement as there is not enough margin for the layout. The ESD robustness has not been proven yet, but the ESD structures were developed according to an already existing I/O-cell from an ARM I/O-library for this technology.

 

« back

back to top