Cadence fatal error: MN7. mosinsub: 'jsw' has the unusual value of 130 pA/m

[macg84]

Hello at all,
When I run my DC simulation there is this error:
Notice from spectre in 'modn': 'MN7', during hierarchy flattering.
MN7. mosinsub: 'jsw' has the unusual value of 130 pA/m
MN1.min.......
The following branches form a loop of rigid branches (shorts) wher

How can i delete this error?

Thank you

 

[erikl]

jsw has the unusual value

The following branches form a loop of rigid branches (shorts) wher
Thank you

You might have 2 zero-resistance sources in parallel: A stimulus and a (vdc) source ?

 

[macg84]

fatal error

Thank you erikl : )

 

[purnima.somkuwar]

rigid branches (shorts)

hi macg84,
how u resolved this problem ?bcz i also phasing this problem . in hierarchy to give the globle sources input i m using vdc in between vdd and ground . and gave the value to vdc to =5 volt . and the stimulus window i again givine the value to voltage source 5 volt . is this correct or not?
what is the meaning of "You might have 2 zero-resistance sources in parallel: A stimulus and a (vdc) source ?" i m not getting this. plz plz reply as soon as possible . thank you .

 

[macg84]

rigid loop in cadence

Hello,
Your procedure seems to me correct, to solve my problem I have decoupled the two branches of my circuit, but sincerely I did not understand clearly why I gave that bug. Be careful with the gnd of the circuit.I would help you more but i don't know...sorry

 

[erikl]

spectre rigid branches loop

... i m using vdc in between vdd and ground . and gave the value to vdc to =5 volt . and the stimulus window i again givine the value to voltage source 5 volt . is this correct or not?

Not. Only one of these two is necessary (and allowed).

what is the meaning of "You might have 2 zero-resistance sources in parallel: A stimulus and a (vdc) source ?".

Exactly what you have: 2 voltage sources (both with an output resistance of 0 Ohm) in parallel. This is not allowed. (Why? Because already a minimum potential difference - say 5.0000001 - 5.0000000 V - would produce a difference current of infinite value).

Just remove either the vdc source or the stimulus!
Cheers, erikl

 

[purnima.somkuwar]

following branches form a loop of rigid branches

hi friends,
i got this ,whenever we choosing vdc source we define value of it too ,so in the global source option we should not give the value of dc source . if we giving the value here too then this shows fatal .error

 

[macg84]

cadence rigid branches

I had 2 voltage sources (both with an output resistance of 0 Ohm) in parallel. This is not allowed. So i had to separate them