Need to design and simulate a PWM circuit on Mulitsim. Must follow the block diagram shown below:

The constraints must be followed

Must follow the final drive stage

This is what i have done so far... Won't simulate in multisim. Give error codes (singular matrix) etc.

I will upload images below for those who cannot view the images here...

 

This is the error message I get... I wonder if its the way i have the data going from the triangular wave generator (integrator circuit) to the Positive / Negative peak detector...