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Comment by dragontamer | Hacker News Reader

Just to note how common delta-sigma converters are: Arduino's got them for voltage sensing.

I dare say that the most common AD converters are simply delta-sigma converters, especially if 1MHz conversions is fast enough for your tasks.

To get into the 100MHz or above speed (ie: Oscilloscopes, Software defined Radios, etc. etc.) you need to use other techniques.

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When you say "Arduino's got them for voltage sensing," are you talking about the ADC in the ATMega328 that powers most of the Arduino models from the last decade? Because that ADC isn't a ΔΣ, it's a 10-bit successive-approximation ADC.

Ah yes, it seems like I've been mistaken :-(

I distinctly remember that Delta-Sigma was a slow-type of ADC. And I guess I confused it with the one in the ATMega328p.

You're right, it's an ATMega328P, not an ATMega328 like I said.

The ATMega's ADC is pretty slow, like 15ksps at full precision, so I can see why you'd think that!

> To get into the 100MHz or above speed

That gets back to my original point. The spectrum analyzer went into the gigahertz range. I don't think it was delta sigma. It was some multiple sample thing that only worked in the frequency domain.

You can make spectrum analyzers that don't digitize at all, of course.

It might have gone into the GHz range, but I'm guessing with a narrow bandwidth. It's the bandwidth that determines the sampling rate needed.

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