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#1 May 27, 2021
electric
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Joined: 2021-05-27 09:49

Orcad Pspice: How can i change the surface of the transistor ?

Hello,

 

i want simulate the temperature sensor lm335 in Orcad Pspice. In this sensor i have two transistors and i need a surface ratio of A1/A2 = 10.

How can i do that?

 

thank you

Thu, 2021-06-03 00:54
alok
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What do you mean by surface ratio in context of a SPICE model of a transistor? 

Sat, 2021-07-03 07:24
electric
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Joined: 2021-05-27 09:49

I'm currently building a circuit in the simulation software Pspice, for which I am using 2 transistors, among other things. And these must have an area ratio of 1 to 10. So now I looked at the library and the articles of the transistors from Pspice and found that there are no area specifications for the transistors. For example, I selected the PN2221, but there is no information about the area size for this transistor or for any other transistor either in Pspice or anywhere on the Internet.

Why is this size never given? Does it not play a role in most circuits and I am one of the few who use it?
Are there other ways to solve this problem in Pspice?

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