Topic: DSO with a traditional Input stage
I was very interested in the DSO that bunnie and xobs showed some time ago, but also I want to be able to use traditional oscilloscope probes as usually I work with higher voltages and I don't need a lot of bandwidth.
So I have started to design an input stage that should be compatible with bunnie's design. There is still a lot of work to be done, and that's just before starting with the PCB design, but here is part of the schematic:
The single end to differential pair part is mostly the same as bunnie's active probe:
I have also posted this schematic in the eevblog forum as a lot of people there have experience with oscilloscope design.
I would like to have the input stage in an aluminium enclosure, just as many of the USB scopes on the market, but instead of USB, it would connected to the ADC with two SATA cables to the novena and two flat cables (I hope the ADC board could be the same as bunnie's). The enclosure would have of course two BNCs to connect the scope probes and a terminal to connect the enclosure to earth and avoid possible shock hazards. Maybe and external trigger could be added.
The goal is that the input stage withstands 375Vrms and has a bandwidth of about 200MHz, but I have ZERO experience in oscilloscope design, so maybe this will end up blowing up my novena, who knows...
So what do you think of the idea? Anyone with experience in high bandwidth designs?