plotting reverse saturation current(is) of pnp bjt in spectr

[yvk]

Hi,

I am trying to plot the reverse sat current of bjt versus temperature in spectre ade setup of cadence.

'is' is a model parameter for this model bipolar.


doing a dctemp sweep/parametric shows 'is' is constant with temperature (clearly its not so from theory)

any ideas what is missing here?

Thanks,
yvk

 

[Andrew Beckett]

On 08/11/12 14:56, yvk wrote:

Hi,

I am trying to plot the reverse sat current of bjt versus temperature in spectre ade setup of cadence.

'is' is a model parameter for this model bipolar.


doing a dctemp sweep/parametric shows 'is' is constant with temperature (clearly its not so from theory)

any ideas what is missing here?

Thanks,
yvk

I wouldn't expect a _model_ parameter to change with temperature - it's
an input to the model. Sure the model should have a temperature effect
on the saturation current itself - but the "is" parameter is an input to
the saturation current equation.

So you're looking at the wrong thing. Unfortunately I don't believe
spectre outputs the effective saturation current as an operating point
parameter - it does output the various currents themselves (ic, ib, isub).

Andrew.

 

[yvk]

Yes I shouldnt go by the name 'is'(its just model parameter).
So it looks like rev sat current is not available in the OP.


On Tuesday, August 14, 2012 3:05:26 PM UTC+5:30, Andrew Beckett wrote:

On 08/11/12 14:56, yvk wrote:

Hi,



I am trying to plot the reverse sat current of bjt versus temperature in spectre ade setup of cadence.



'is' is a model parameter for this model bipolar.





doing a dctemp sweep/parametric shows 'is' is constant with temperature (clearly its not so from theory)



any ideas what is missing here?



Thanks,

yvk





I wouldn't expect a _model_ parameter to change with temperature - it's

an input to the model. Sure the model should have a temperature effect

on the saturation current itself - but the "is" parameter is an input to

the saturation current equation.



So you're looking at the wrong thing. Unfortunately I don't believe

spectre outputs the effective saturation current as an operating point

parameter - it does output the various currents themselves (ic, ib, isub).



Andrew.