請教大家一個問題

jswon

圖片是paper上op的bode plot請大家幫我看看，這樣的opamp到底會不會震盪??
實心線的頻率響應 在phase = -180時，gain > 1
但是paper中宣稱這樣是穩定的，讓我很困惑
請大家幫幫忙了，為什麼這樣的響應，是穩定的

bode plot

buckaroo

stalbe
it depends on how you measure the loop AC response
the way u use is assume the feedback is negative feedback, neglect the "-" minus polarity.
the way the author used is just simulate the loop gain and phase, include the "-" minus polarity, so, you should observe the phase margin when phase=0deg instead of 180deg;

lovexxnu

2L is correct, PM in loop gain is decided by 360 phase shift, not 180.

wulong527

study~~

guanjun001

实际上不管怎么连。只要能保证输出节点的
低频相位到高频相位的变化不超过180度
那么这个电路就不会振荡。