Optikon
New Member
I'm brainstroming topologies for a circuit that can perform the following:
1) Maximum differential signal can be as high as 300V, either polarity. (300 peak) AC or DC
2) For AC measuring, bandwidth required is at least to 100kHz, faster would be even better. Needs to be "good" beyond 100kHz to get a clean 100kHz measurement (low distortion, say <0.1%)
3) Measurement circuit must not load input signal. I.e., high impedance, how high? not sure yet but you get the idea.. the higher the better over frequency.
4) output will get scaled to a 10V peak (FS). 300V in = 10v out.
5) all the usual nice things like good linearity, low drift etc... I'd be willing to compromise on some of this though if a tougher problem is solved like the relatively high bandwidth.
Well, I think this is a tough nut to crack. I've considered high voltage input instrumentation amps and my own discrete versions of the same. I'm not too happy with this idea mainly because of the god-awful bandwidths of such contraptions..
Now I'm considering a discrete transistor high voltage front end stage. (I think High voltage mosfets are a must and biasing them is a drag.)
Who's got ideas? While I try and work this out, I'll entertain any thought fragment, or block diagram or comments. Much appreciated!
Oh, one more thing, this is a from scratch design so I do not have restrictions on things like power supplies available etc.. (although, I dont wanna have to make a 300v+ supply - thats ugly in many regards) and I'll consider doing whatever might work..
Thanks!
1) Maximum differential signal can be as high as 300V, either polarity. (300 peak) AC or DC
2) For AC measuring, bandwidth required is at least to 100kHz, faster would be even better. Needs to be "good" beyond 100kHz to get a clean 100kHz measurement (low distortion, say <0.1%)
3) Measurement circuit must not load input signal. I.e., high impedance, how high? not sure yet but you get the idea.. the higher the better over frequency.
4) output will get scaled to a 10V peak (FS). 300V in = 10v out.
5) all the usual nice things like good linearity, low drift etc... I'd be willing to compromise on some of this though if a tougher problem is solved like the relatively high bandwidth.
Well, I think this is a tough nut to crack. I've considered high voltage input instrumentation amps and my own discrete versions of the same. I'm not too happy with this idea mainly because of the god-awful bandwidths of such contraptions..
Now I'm considering a discrete transistor high voltage front end stage. (I think High voltage mosfets are a must and biasing them is a drag.)
Who's got ideas? While I try and work this out, I'll entertain any thought fragment, or block diagram or comments. Much appreciated!
Oh, one more thing, this is a from scratch design so I do not have restrictions on things like power supplies available etc.. (although, I dont wanna have to make a 300v+ supply - thats ugly in many regards) and I'll consider doing whatever might work..
Thanks!