Ground-Referenced Single-Ended Signaling: Applications for High-Density, Short-Haul Communication Systems

In this article, we discuss how ground-referenced signaling (GRS) avoids many of the challenges associated with SE signaling, thanks to a unique transmitter (Tx) topology, to produce a link with high reliability, high information density, and high energy efficiency for short-reach applications. GRS-based short-reach links also use a simple but robust clock-forwarding scheme to cancel jitter without the need for a clock recovery system at the receiver (Rx), thereby, saving significant power. This approach also provides high-bandwidth jitter tracking, which we take to the limit by matching circuit delay and delay sensitivity for clock and data lanes at both ends of the link. Codesign of the link circuitry and channel takes full advantage of the ability to match the insertion delays of multiple data/clock lanes within the short-reach interconnect. The low attenuation that can be achieved in a codesigned channel is leveraged to achieve a simple, robust, and low-power design.