[sdiy] VCO reset time

[Don Tillman]

   > Date: Mon, 7 Jun 2004 13:44:23 +0300 (EEST)
   > From: Antti Huovilainen <ajhuovil at cc.hut.fi>
   > 
   > Isn't sawtooth based PWM same as triangle PWM that is phase
   > modulated?

That's right.  For the triangle-based PWM wave, the fundamental and
all its harmonics are in phase with the base triangle.  And the
sawtooth-based PWM wave's phase moves back and forth with the
modulating voltage.

   > Pulse wave is equal to two sawtooth waves with delay and opposite phases.
   > In triangle based PWM you phase modulate both saws in opposite directions,
   > while in sawtooth based PWM you only modulate one saw. 

True, that's a good visualization.

   > Thus to me it seems that sawtooth PWM is same as PWM but in
   > addition to changing the pulse width (as with triPWM) you also
   > change the midpoint of the pulse (same as phase modulating the
   > triPWM).

Yep.

  -- Don

-- 
Don Tillman
Palo Alto, California
don at till.com
http://www.till.com