KashAMSD
Newbie
Hello, I was designing an Error Amplifier(Compensation) for Closed loop voltage mode Buck Converter taking a Texas Instrument document*(page 6,7,15,16,18,20,21) as a guide. I understood the design procedure and completed the design. But i had some questions that I needed clarifications of.
1. How can we determine whether we need a Type II or III compensation? What determines how much phase boost we need for a specific Buck Converter?
(I know that for about 90° phase boost we need Type II & for around 180° phase boost we need type III compensation. But the question remains, how do we know how much phase boost we need for a specific buck)
2. For all the Type I, II & III compensations, we need to place a pole at origin. We know, placing a pole at origin mitigates the steady state error. But a pole at origin also causes a system to go unstable. So, how come the close loop buck doesn't become unstable even if we have a pole at origin in the Error Amplifier?
3. Why do we need to set the 2nd pole of compensator at half of switching frequency?
*https://www.ti.com/seclit/ml/slup340/slup340.pdf
I'm new to the forum. I apologize for inconvenience and thanks in advance.
KashAMSD
1. How can we determine whether we need a Type II or III compensation? What determines how much phase boost we need for a specific Buck Converter?
(I know that for about 90° phase boost we need Type II & for around 180° phase boost we need type III compensation. But the question remains, how do we know how much phase boost we need for a specific buck)
2. For all the Type I, II & III compensations, we need to place a pole at origin. We know, placing a pole at origin mitigates the steady state error. But a pole at origin also causes a system to go unstable. So, how come the close loop buck doesn't become unstable even if we have a pole at origin in the Error Amplifier?
3. Why do we need to set the 2nd pole of compensator at half of switching frequency?
*https://www.ti.com/seclit/ml/slup340/slup340.pdf
I'm new to the forum. I apologize for inconvenience and thanks in advance.
KashAMSD