In IC Layout , what is the difference between transistor multipliers and fingers?

Status
Not open for further replies.
B

bio_man

Full Member level 2
Joined
Mar 30, 2010
Messages
144
Helped
2
Reputation
4
Reaction score
4
Trophy points
1,298
Activity points
2,698
Hi folks,

In IC Layout , what is the difference between transistor multipliers and fingers?
I want to layout bunch of transistors with W/L= 21/0.6 and some wider gates (63/0.6). To save area and decrease Rgate, I decided to do fingering. However, I got confused between the two, multipliers and fingers. I attached the ayout and extracted view of the two ways. I layout one transistor using 2 multipliers with W=10.5um and the other one with two fingers also W=10.5um. The extracted devices shows the same, So can I say multiplier and fingers are the same?



Thanks
 

Attachments

  • Layout.png
    36.3 KB · Views: 584
  • extracted.png
    55.6 KB · Views: 698

For "digital" and "mixed signal" kits there may be no
practical difference.

For "RF" where you care more about Cgd and Cdb than
almost other thing, you would be way worse off with
m=N nf=1 FETs than with m=1 nf=N FETs, because the
total Cdb will be nearly double (with linearity especially
a concern).

Extract "permute" rules govern how the equivalence of
different finger*multiplier arrangements are assessed.
 
No, they are not the same. The transistor on the left has contacts in the middle which will allow you to parallel the two transistors. The transistor on the right has no contacts but a smaller gate to gate spacing. This may simply be due to an option on the transistor pcell.

What technology are you using?

Rob
 
Reactions: bio_man

    B

    bio_man

    Points: 2
    Helpful Answer Positive Rating
    S

    Shr@v@n

    Points: 2
    Helpful Answer Positive Rating
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…