I had a conversation of A/D converters recently, we speculated on the fastest topology, it must be interleaved sampling.
In principle, one could interleave without limit; go to higher and higher time resolutions, attain proportionately higher sampling rates. What's the limit, in practice, given an unlimited budget?
We must assume a quantization, let's say 6 bits, but you might suggest another.
Am 18.03.23 um 23:18 schrieb RichD:
Keysight has a 100 GHz BW scope with interleaved samplers IIRC.
Gerhard
søndag den 19. marts 2023 kl. 00.04.19 UTC+1 skrev Gerhard Hoffmann:
Keysight UXR-Series, MSRP "only" $1.3mill
I don't know what the actual limits are, but the two issues are jitter on the clock, and the sampling window. We like to think in absolutes, but even the fastest sample and hold has a timing window.
Since A/D converters are not identical, they might produce slightly different digital values even from a steady analog voltage. Thus you might get at least 1 LSB high square wave from a constant input. Thus adding sufficient dither is critical.
I suspect so, also that's what the fastest oscilloscopes do.
I remeber seeing traces branching and fanning out to 64 or some other crazy number of ADCs
This is solvable by calibration, at the expense of a minor part of the full scale (say twice the worst case error you want to correct). I did something similar to get integral nonlinearity from 2-3% down to below an LSB for a 13 bit convertor ...nearly
30 years ago...(can't be true that time passed, can it).The real issue is the one Rick talked about, sampling window/accuracy and of course clock jitter. And budget... :).
Go on.
Cheers
Phil Hobbs
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