UPDATE, 17/04/2024: These are now available at
http://www.lasmux.com/product/single-ended-active-probes/. 2.7GHz probe.
I've been working on an active probe design for around a year. The goal started off as creating a DC-coupled active probe to support a photon counting sensor I am also working on, but it was a very fun project and I spent so much time on it that now the plan is to sell it. Could I have some feedback on the probe/performance, and on the contents of the datasheet, before I start buying the first batch of parts... which will be quite expensive.
I have another post that I'm putting together where I'll go into the development process a bit more.
I'm making two versions, a 1GHz version, and a 2GHz version.
The datasheet is here: https://www.lasmux.com/wp-content/uploads/2023/07/LD-ASP-1G_2G.pdfQuick specs:
Bandwidth: DC-1GHz, DC-2GHz
Input capacitance (measured at 1GHz): 0.7pF
Attenuation: 20x
DC input resistance: 1Mohm
1GHz version frequency response (linear and log axis):
2GHz version frequency response (linear and log axis):
Tip input impedance of both probes, depending on which ground lead is fitted:
The resistive ground lead can be used to stop a resonance developing on the ground connection, which reduced the input impedance above 1.5GHz. I talk about this a bit more in the datasheet.
In terms of step response for the system, I've 'only' got a 500MHz oscilloscope, so can't properly test the rising edge speed unfortunately. This is the probe measuring a 50 ohm terminated 100MHz signal, with a <100ps rise time. This greatly exceeds the bandwidth of the scope so there's some ringing. The trace looks basically identical if I measure the signal directly by the oscilloscope.
Currently I'm aiming for around £150 for the 1GHz version, and £185 for the 2GHz version.