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Modeling >> Semiconductor Devices >> how to use the M factor for bjt's
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Message started by halvoth on May 20^th, 2003, 6:21am

Title: how to use the M factor for bjt's
Post by halvoth on May 20^th, 2003, 6:21am

I need to change the m factor for my bipolar transistor. I run analog design environment 4.4.6 and AMS HIT-KIT 3.50 (---I use the 0.35uBiCMOS process).

The M field is disabled for my bjt's; I have to manually change the netlist to use other m factors.

Does anyone know how to enable the m-field for the bjt's ?????

thomas

Title: Re: how to use the M factor for bjt's
Post by Andrew Beckett on May 27^th, 2003, 10:02pm

Contact the kit provider and ask them to enable it.
The workaround you mentioned on comp.cad.cadence
of using M1<0:4> to represent m=5 is rather less
efficient for the simulator, and VirtuosoXL can automatically
handle splitting the device based on the m-factor (which
is the reason that AMS have removed the ability to change
the m factor).

Regards,

Andrew.

Title: Re: how to use the M factor for bjt's
Post by Andrew Beckett on May 27^th, 2003, 10:04pm

Note, if you don't mind hacking the kit, then this will be
a case of modifying the CDF (Tools->CDF->Edit CDF)
for the appropriate component, selecting the
component, going to the m parameter in the parameters
section and changing the editability (I'm guessing here,
but I'd have thought that would do it).

Regards,

Andrew.