help for SS corner simulation with spectre Cadence

[calliste]

Hi all,

I'm designing a telescopic cascode amplifier for a charge preamplifier. It works very for typical paremeter and also for FF FS FS corner simulation.

However it works abnomally with SS corner simulation. Does anyone have an idea about what to do to have my circuit works in all corner.

Any help will be really appreciated!!

Thanks!!

 

[JoannesPaulus]

Some of the transistors go out of saturation: in the slow corner your VTH is higher. Look at the bias points and fix your bias circuit.
As a general consideration, it is usually easier to start the design in the slow corner, low voltage, high temperature. If you can meet the specifications there, it is somewhat likely that you'll meet them in all the other corners (with small modifications).

 

[calliste]

Thanks JoannesPaulus,

I checked my bias circuits and the problem came from the bias of the cascode that was to low in SS corner, causing the input transistor to be out of saturation.

Best regards!!