Electronic – Homebrew differential ‘scope probe

high frequencylvdsoperational-amplifieroscilloscopeprobe

I may be able to get my hands on an old 600MHz LeCroy oscilloscope. However, it doesn't have any probes.

Is it feasible to make an active differential probe for it using a high-speed op-amp, like the THS3201DBVT? It has a 1pF input capacitance, 1.8GHz bandwidth and is for arbitrary waveform measurement applications. I would like to examine a 100Mbps LVDS signal.

The basic idea would be to mount the amp on a little PCB with a couple of parallel gold probe pins, power it off a local +-6v battery, and use a short piece of coax to connect it to the 'scope.

Best Answer

This will work. Since it is current mode you don't have to worry about gain roll-off with increasing frequency.

However make sure the battery is referenced to the same ground as the baord.