@User I followed your suggestion, but V1 waveform still does not look right between 181ns and 211ns. Why ?

@promach you are telling it to be 0 at 181ns and 1.8V at 211ns. which is a very slow ramp. For a fast ramp you could do replace the 181ns with 210ns and then the rise time will be 1ns instead of 20ns like you have now