about solving the warning of .ac analysis

[nieco]

when i used hspice ac analysis, .pz,
there is a warning, that is "**warning** zero analysis stopped - iterno .gt. 100".
and the position of poles and zeros in the .lis do not match with the simulation graph.

how can i solve this problem?
thx a lot.

 

[Btrend]

it seems that the simulator stop analysis after 100 times of iteration.
usually, this is convergent problem.
u had better check the bias points, especially those bias points of high gain stage .

 

[sunking]

enlarge the number of iteration
reduce the precision