I need to use sg3524 inverter circuit. Requirements of the output adjustment range from 0vAC to 220VAC. I find the circuit but do not know how it works. And how to calculate the stages: from the pulse generator block, step response, ... Please anyone help.Thank!
Are you referring to the Microsemi SG3524 PWM controller? If so I would start by reading the data sheet.
As far as understanding how a Microsemi SG3524 based inverter circuit works, I would start by reading up on inverter circuits and their operation. Just search for Inverter Circuit design on Google or some other search engine and get reading.