Spice simulation problem (option pivot)

Hello,

I'm simulating a Sigma-Delta modulator in Hspice and I get the
following error:

*error*: maximum conductance on node 0:ecompar =(
0.0000D+00)
is less than pivtol. check hookup for this node. set option
nopiv and rerun.

I set .option NOPIV and rerun, but still get the same message. I am
using voltage controlled sources as opamps :
***************************
Rin in integr_n 1k $interg_n =>negative input of
intergrator's opamp
Eintegr compar_n 0 OPAMP GND integr_n $compar_n =>negative input of
comparator's opamp
Cint integr_n compar_n 30p
Rintegr integr_n fdb 1k $fdb =>feeback from the latch
Ecompar latch_in 0 OPAMP GND compar_n MAX=5 MIN=0
***************************

the rest of the circuit is 8 mosfets implementing a latch.

Does anyone have any idea why I get this message, and why setting the
option NOPIV is ignored??

Thanks

George ( mail: giorgos.puiklis at gmail.com)

 

[Fred Bartoli]

giorgos.puiklis@gmail.com a écrit :

Hello,

I'm simulating a Sigma-Delta modulator in Hspice and I get the
following error:

*error*: maximum conductance on node 0:ecompar =(
0.0000D+00)
is less than pivtol. check hookup for this node. set option
nopiv and rerun.

I set .option NOPIV and rerun, but still get the same message. I am
using voltage controlled sources as opamps :
***************************
Rin in integr_n 1k $interg_n =>negative input of
intergrator's opamp
Eintegr compar_n 0 OPAMP GND integr_n $compar_n =>negative input of
comparator's opamp
Cint integr_n compar_n 30p
Rintegr integr_n fdb 1k $fdb =>feeback from the latch
Ecompar latch_in 0 OPAMP GND compar_n MAX=5 MIN=0
***************************

the rest of the circuit is 8 mosfets implementing a latch.

Does anyone have any idea why I get this message, and why setting the
option NOPIV is ignored??

I didn't check the rest but the option syntax is

..options ... (notice the final 's').

On my spice (which isn't hspice) the misspelled .option line is simply
ignored without any warning.

--
Thanks,
Fred.