Selecting High Bandwidth Probes
Probing solutions are being pushed to the limit by high-speed digital applications. With the increase in system bandwidth, the signal’s edge speed gets faster and the volume of components and chipsets size become smaller. At the same time, the PCB layout tends to become more complicated. Such trends are a challenge to probing solutions. Higher performance calls for greater care in the selection of probes.
A perfect oscilloscope probe will offer an exact imitation of the probed signal. However, probes are embedded in the circuit which is under test, leading to probe loading. On a data sheet, a probe might show very impressive performance, but this may be under perfect conditions. In reality, probing involves the use of accessories for attaching to the tips of the probe and the performance might not be as good as the published data.
When you are selecting an embedded high bandwidth probe, it is vital to remember that the loading characteristics of the probe might not be the same as a traditional probe. You will find that high bandwidth probes such as InfiniiMax III (or III+) might showcase a varied input impedance feature. While selecting high bandwidth probes, users need to ensure that the process of probe loading is within tolerable limits.