Signal integrity performance degradation due to temperature variation in systems with re-drivers

Re-drivers are widely used in extending the solution space in high speed applications. However, recent lab data shows that the ambient temperature variation can lead to ~40mV degradation of the eye height at the receiver side on single re-driver system. In this paper, the authors will share key learnings of thermal impact on systems with both single re-driver and cascaded re-drivers. From these cases, the eye height is greatly reduced when temperature increases. This variation is due to resistance shifting of the output buffer, while most re-driver models do not account for it. An effective approach is applied to fine tune the equalization settings in the cascaded re-driver system. The learnings, together with the proposed approach, can help designers to design a robust, high performance, and cost-effective high speed link with re-drivers such as SAS-3, SATA-3, PCIe and USB, etc.