@ericgibbs

.... or how about this?
View attachment 216929

@ericgibbs - If I use a sine wave to modulate the PWM carrier can an ac analysis sweep be done of the modulation signal to get a frequency response. An issue is I want my modulation signal to be between 0V and 1V. I'm not sure what levels are used for an ac sweep.


Mod link to old thread
https://forum.allaboutcircuits.com/...oltage-and-convert-to-pwm.172663/post-1549630

 

hi eu'
Please post your LTSpice asc file.
E

 

not sure what levels are used for an ac sweep.

An AC sweep uses linear models and can't be used for switching/transient analysis, such as a PWM circuit requires.
You can do something like this.