请教bandgap 问题

yihang

请教 设计bandgap时， phase=-180C 和 gain=0db 时对应的频率是否需要特别关注，一般设计到多少比较合适？
感谢！

eilleenyang

我们一般PM>60C, GM>10dB.PM, GM 涉及amplifier的稳定性，当然要特别关注。
在google上搜：Phase Margin and Gain Margin，得到
Phase margin and gain margin are different ways of specifying the stability of the circuit.
Gain margin of an amplifier is the gain at the point where there has already been a phase shift of 180º. If the gain at this point is more than unity, then the amplifier is going to be unstable.
This is because once there has been a 180º phase shift, the feedback is actually going to be positive. In terms of dB that means negative gain is going to be stable at a 180º phase shift.
Phase margin is the difference between the phase when gain is unity ( 0 dB) and 180º. If at 0 dB the phase lag is greater then 180º, then the amplifier is unstable. This is due to the reason explained previously. It would imply that the gain margin is positive.

wxwttf

按你叙述像是增益裕量的意思

yihang

感谢两位，那phase=-180c and gain=0db对应的带宽需要特别注意么?
有没有说需要设计到几MHz?