To design today’s increasingly complex digital systems, engineers need sophisticated analysis tools. For system validation tasks, most engineers rely on logic analyzers. As system speeds have skyrocketed and system complexity has multiplied, logic analyzer vendors have boosted instrument performance and functionality to give engineers the capabilities they need. In many cases, the logic analyzer has more than adequate performance for the task at hand, but the physical probe connection from the analyzer to the target system causes a performance bottleneck. If the signals received by the logic analyzer are degraded, the analyzer’s powerful triggering and analysis tools are useless.

This application note explores basic probing concepts you need to master a successful logic-analyzer-probing connection. We examine probe form factor choices, probe loading and signal quality concerns, and common problems associated with grounding. Finally, we discuss two common mistakes: probing at the wrong line location and choosing the wrong interconnect.