Understanding Probe Calibration Methods

If there's a topic concerning probes that causes confusion, questions, and misunderstandings, it's loading. It would be a much simpler world if attaching a probe to a circuit under test had no effect on either the signal being measured or the device the probe is connected to. Unfortunately, the world isn't quite so simple.

Making Sense of Probe Terminology

As oscilloscope users, we know that the probe is a critical element in getting signals from the device under test into the instrument. The ideal probe would have perfectly flat magnitude response and perfectly linear phase response across its entire frequency range. Unfortunately, that probe, though striven for by all oscilloscope manufacturers, does not exist.

Why Should You Measure Jitter?

Figure 1: Designing a serial-data channel with first-pass
success means analysis and mitigation of jitter sources

As mentioned in an earlier post on some basics of jitter, the bane of serial-link design is a signal that doesn't arrive at its destination when it should, whether early or late. The goal of serial-link design and implementation is to transmit data with as few bit errors as possible. Thus, analyzing jitter is a key element of achieving first-pass design success.