huashizng
Newbie level 6
Hi,all . now i am simulating current loop ac stability for the charger. the loop model schematic is listed below. i have two questions about it.
First, according my understanding, the loop gain is A*F= A*10*10. So i should find out phase margin at (A*F)=0db. but leader advise me to detect phase margin at A=0db. Why should i do so? the another 40db gain is also in the current loop. why should i detect phase margin after 40db gain is deleted?
Second. we can see Li battery as a large capacitor(for example, 100F) in series with a resistor. but there is no large capacitor in this battery model. why?
First, according my understanding, the loop gain is A*F= A*10*10. So i should find out phase margin at (A*F)=0db. but leader advise me to detect phase margin at A=0db. Why should i do so? the another 40db gain is also in the current loop. why should i detect phase margin after 40db gain is deleted?
Second. we can see Li battery as a large capacitor(for example, 100F) in series with a resistor. but there is no large capacitor in this battery model. why?