Solution to the errors from Tanner/Tspice

[blowfish]

Hai,

Can anyone tell me the exact meaning of this error and warning which was generated by the TANNER tool/TSPICE . I was executing a circuit for output , when i got this error . I need the meaning of this error and method/procedure to rectify the problem.

Any help would be appreciated !

The errors generated are :


Fatal DC OPPT : DC non-convergence (source step smaller than minimum=1e-010)
Fatal DC OPPT : Try increasing abstol=5e-010, reltol=0.0001, and/or numnd=10
Warning DC OPPT : Check C:\Tanner software\tanner\mohana sundaram\analog dll\dll_top.dc for problem nodes

 

[hemal]

hi

even i am getting the same error.

can anyone suggest the solution?

thanks in advance.

 

[antonio_eda]

Check your circuit carefully: bias, connections, polarization of devices. The algorithm cannot find a solution with not so usual circumstances...

 

[hemal]

hi

i changed the parameters as below.

.options absi=5e-07
.options reli=0.01
.options numnd=3000
.options chargetol=1e-012

and now i am getting the desired output. i was trying to make a %N counter for the PLL.

can you tell me how obove parameter effect when calculating the initial condition of the circuit?

regards,

hemal

 

[abhinav g]

i am getting " missing MOSFET definition for 'NMOS' " in s-edit of tanner v13 when i run simulation for any ckt involving NMOS ..is it a problem with the library file ?