Improved reference clock connection interface for prototype IEEE 1588 master clocks

In this paper we present a fundamentally redesigned Global Navigational Satellite System (GNSS) receiver to master clock interface based on our previous design for IEEE 1588 Precision Time Protocol (PTP) master clocks. The new design is optimized for modern timing GNSS receivers; including GPS, Galileo, and GLONASS GNSS; which provide better timing accuracy and precision than previous generic navigational or even older timing GPS receivers. The new design is required because new timing GNSS receivers have lower than 10 ns error while the errors introduced by the previous interface solution is one or two magnitudes bigger than that, causing degraded system wide timing performance for new systems. Better performance is achieved by an error source analysis and a delicate component selection based on the results of the analysis, and in addition, timing oriented PCB routing. Furthermore, the new design is more compact, integrated with a CPU board, and therefore, ready to be deployed in prototype applications. The paper also provides an initial performance evaluation of the improved reference clock interface.