Phase mod with PWM

[Martin Czech]

:::Is there a way of generating PWM without the phase modulation that seems
:::to accompany it? I can understand that generating your PW from the saw
:::output would generate a phase modulated signal. I believe, using a

I don't know if I understand your problem, it seems that deep PWM causes
a perception of FM, which you don't like.

Now, PWM could be done with two 50% duty cycle oscillators, slighly
detuned and logical ANDed. If the two waves are in phase  you get 50%
duty cycle, out of phase means 0%. A kind of nonlinear beating (of course
this would be stupid, this is only an example).

In order to modulate you have to phase shift one of the
waves. Unfortunately frequency is change of phase, or :

F=d/dt P

So , changing the phase implies changing frequency at least of one of
the components, and this is audible.

So , from this reasoning I'd say: No, you can't get one without the other.

m.c.