According to the U-111
when the Ct voltage reach the error amplifier output the PWM will turn off, and the CT will keep charging until reach the upper threshold. in the datasheet the dead time is the capacitor discharge time. So the line between 2 and 3 called dead time. what is the line between 1 and 2 called what? and if I add the sync pulse in there,which mean the capacitor will discharge immediately right?