nidare
Newbie level 6
Hello
I have been getting some strange results when trying to do noise analysis on my opamp design.
The frequency characteristics looks ok when doing stb analysis with unity gain at 1 MHz with 65 degree phase-margin, and behaves nicely in transient.
When doing the noise analysis i see a strong increase of noise from around 200 KHz and all the way to 1 GHz. Anybody have any ideas what can cause this when the stb analysis shows a sharp rollof of gain at frequencies above 1 MHz?
If i turn off the flicker noise in the noise contributions menu i get the following.
The design uses Multi-Path hybrid nested miller compensation and I suspect this can have something to do with it, but I dont understand how this can happen when the stb shows very little gain for frequencies beyond 1 MHz.
I have been getting some strange results when trying to do noise analysis on my opamp design.
The frequency characteristics looks ok when doing stb analysis with unity gain at 1 MHz with 65 degree phase-margin, and behaves nicely in transient.
When doing the noise analysis i see a strong increase of noise from around 200 KHz and all the way to 1 GHz. Anybody have any ideas what can cause this when the stb analysis shows a sharp rollof of gain at frequencies above 1 MHz?
If i turn off the flicker noise in the noise contributions menu i get the following.
The design uses Multi-Path hybrid nested miller compensation and I suspect this can have something to do with it, but I dont understand how this can happen when the stb shows very little gain for frequencies beyond 1 MHz.