Re: [AH] Synthex oscillators

From Andre Majorel
Sent Sat, Sep 1st 2018, 18:20

On 2018-08-31 19:26 -0700, Brian Willoughby wrote:

> 8-bit counter makes it digital, even though the DAC is cheap.

Depends what makes a VCO digital. If it is having a DAC in the
signal path, yes. If it is having its frequency controlled
digitally, not necessarily.

> A pure analog ramp oscillator still has a cap charging and
> getting reset, so that?s not exclusive to DCO. The difference
> between a DCO and VCO is that the DCO resets based on a
> digital crystal oscillator that has been divided down, while a
> VCO resets based on an analog voltage crossing an analog
> threshold (think: comparator).

Agreed.

> One step further away from a VCO than a DCO would be an
> accurate characterization.

Unless the clock that increments the counter is derived from a
VCO, in which case it's arguably the opposite.

-- 
André Majorel http://www.teaser.fr/~amajorel/