[time-nuts] DIY TimePod
chris at chriscaudle.org
Mon Jun 13 23:17:41 EDT 2016
On Mon, June 13, 2016 9:38 pm, Bruce Griffiths wrote:
> If the quantisation noise is random and spread uniformly over the Nyquist
> bandwidth (~40MHz??) then the noise floor is about -82dBc/Hz.
How do you spread the quantization noise randomly with a one bit
quantizer? I'm mostly familiar with single bit quanitizers in the context
of audio range delta-sigma converters where the quantizer is in a feedback
loop to move most of the noise to a higher frequency range. That also
requires a clock much higher than the minimum nyquist requirement.
Maybe I need to see a block diagram of what is being described. Where is
the clock for the ECL flip-flop generated? I don't recall seeing a
description of what the effective sample rate will be, or the highest
clock signal accepted for analysis.
> With a high resolution RF ADC internal noise is usually sufficient
> (>= 1 lsb)) to ensure this.
Can't really dither to >= 1lsb when lsb=msb (single bit quantizer).
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