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You need to test, we're here to help.

19 December 2018

Using 50-Ohm Coax From DUT to Oscilloscope

A coaxial cable presents high impedance at low frequencies but acts as a transmission line at higher frequencies
Figure 1: A coaxial cable presents high impedance at low
frequencies but acts as a transmission line at higher frequencies
In our recent exploration of 10x passive probes, we've determined that while these types of probes are great general-purpose tools, they're not necessarily going to do the job in specialized measurement circumstances. They're relatively low-bandwidth, low-SNR probes that impose some limitations and, in some scenarios, can deliver potentially misleading or erroneous measurement results if used without clear understanding of their capabilities.

12 December 2018

Squeezing More Bandwidth From a 10x Passive Probe

Shown is a comparison of inherent oscilloscope noise and noise at the shorted tip of a 10x passive probe
Figure 1: Shown is a comparison of inherent oscilloscope
noise and noise at the shorted tip of a 10x passive probe
Now that we have a better understanding of what's happening under the hood of a 10x passive oscilloscope probe, we can sum up its key characteristics. The first thing to know about such probes is that they offer relatively low bandwidth (<100 MHz). This is largely a result of the probe's tip inductance.