A question about NPN tr layout

Status
Not open for further replies.
L

llbaobao

Member level 3
Joined
May 19, 2008
Messages
55
Helped
5
Reputation
10
Reaction score
0
Trophy points
1,286
Visit site
Activity points
1,595
npn tr basic

I saw some bipolar layout of others, and found that some NPN tr's collectors are drawn like a comb style!

Does it makes some senses to draw the collector of a NPN tr like a comb?

Thanks for any reply!
 

Multifinger devices improve things like overall base
junction area, debiasing (end fed metallization I*R)
and so on.

A collector comb without E, B between them would be
pretty pointless.

Depending on the application you may like a
C-B-E-B-C (minimizing base resistance, like for low
noise) or C-E-B-E-C (minimizing collector resistance
instead).
 

    L

    llbaobao

    Points: 2
    Helpful Answer Positive Rating
Thank you for your reply.

I attach a figure.

there are also other nearly the same comb like collector in the layout.

Is there any other meaning?

 

This is a guess, but is this a vertical PNP where the substrate is used as a grounded collector? This fingered area may be p+ connected to ground.
 

That is one crazy looking "transistor".

Perhaps the finger is really a second emitter and the
notching, an attempt to match emitter-base perhipery
as well as area (a simple rectangular scaling, would
not hit both simultaneously). Though my preference
would be to instance-ratio identical polygons if an
integer ratio was the desired outcome).
 

The leftmost line is ground line. This is certain.

according to the circuit analysis, the comb like area is collector, that's all.

of course, such analysis maybe wrong.
 

Status
Not open for further replies.

Similar threads

Menu
Log in
Register
Cookies are required to use this site. You must accept them to continue using the site. Learn more…