[sdiy] Digital VCO

[Magnus Danielson]

From: "Paul Perry" <pfperry at melbpc.org.au>
Subject: Re: [sdiy] Digital VCO
Date: Mon, 24 Apr 2006 21:56:39 +1000
Message-ID: <00f801c66796$25d047c0$0a01a8c0 at frostwave>

> But if you use a low frequency VCLFO a a modulator, isn't
> the stepping obvious?

Depends on your resolution. If you have a digital VCLFO, you can have a phase
resolution of say 64 bits (or more) for virtually no cost whatsoever. Scaled to
the appropriate amount into a phase-accumulator say 64 bits again you can make
the steps fairly small. Infact, if you run both of them in the same sampling
frequency and have sufficient of phase accumulator dynamics, your VCLFO would
update the VCO each sample, even if it is by a ridicolously small amount.

Thus, you can design your way out of the problem if you care to.

When I toss a 1 uHz sine out of my test-generator, my DMM ticks and ticks all
the time. Maybe not every sample, but it could be done.

Cheers,
Magnus

> paul perry Melbooune Australia
> ----- Original Message ----- 
> From: "Richard Wentk"
> > The big advantage with digital is that
> > it's trivially easy to turn a digital VCO into a digital VCLFO with a
> cycle
> > time that goes as low as you want.
>