temperature sweep in Spectre

Hi
Running MMSIM61

I have a diode model with 'rs' defined by a cubic temperature function
(i.e. const+lin*temp+quad*temp^2 *cub*temp^3)

When I sweep the temperature in a simulation it works O.K.

When I try to run dc sweep simulation at a selected temperature I get
an error saying that 'rs' is less than or equal to zero.

It turns out that with the coefficients I'm using in my function the
value of rs does indeed go negative above a certain temperature.

Why does spectre not bother about this when the temperature is sweep
but the at spot temperatures spectre won't run

Cheers
Martin

 

[Andrew Beckett]

On Tue, 31 Jul 2007 07:31:58 -0700, mgrossman@zetex.com wrote:

Hi
Running MMSIM61

I have a diode model with 'rs' defined by a cubic temperature function
(i.e. const+lin*temp+quad*temp^2 *cub*temp^3)

When I sweep the temperature in a simulation it works O.K.

When I try to run dc sweep simulation at a selected temperature I get
an error saying that 'rs' is less than or equal to zero.

It turns out that with the coefficients I'm using in my function the
value of rs does indeed go negative above a certain temperature.

Why does spectre not bother about this when the temperature is sweep
but the at spot temperatures spectre won't run

Cheers
Martin

I see this one has been logged as a service request, and is being worked out
with R&D, so I won't comment on it here.

Regards,

Andrew.
--
Andrew Beckett
Senior Solution Architect
Cadence Design Systems, UK.