Cross-Talk Issues in Time Measurements

The enormous diffusion of Time-Mode circuits, in particular Time-to-Digital Converter (TDC) time measurement circuits, and at the same time the dizzying increase in parallel channels required by the most recent applications, for example in the automotive and digital imaging fields, brings the problem of electromagnetic interference between channels ever more to the fore. This phenomenon, generally known as Cross-Talk (XT), is particularly critical given the increase in the operating frequency and density of systems components, and its effect on the timing parameters in TDC measurements is investigated. Considering the time measurements, XT creates temporal shift on the physical events from which the timestamps are extracted; in this manner, an error in the measurements is generated. In order to detect the XT phenomena, a methodical analysis based on Code-Density Test (CDT) is performed; in this terms, two different typologies of XTs are investigated, which are correlated and uncorrelated XT. Furthermore, a TDC board is used as case study and all the XT sources are detected and classified. Thus, a classification of the importance of the different sources of XT is achieved and a solution to minimize the different causes is proposed.