[SOLVED] Optimal numbers of fingers in MOS layout

[anindya1012]

Hi,
What can the optimal number of fingers in layout? say I have to layout a mos of 75u/150n (W/L) ratio, what can be the optimal number of fingers? if I put a large number of fingers, would it cause a problem in layout?

 

[bgangur]

Hi,
What can the optimal number of fingers in layout? say I have to layout a mos of 75u/150n (W/L) ratio, what can be the optimal number of fingers? if I put a large number of fingers, would it cause a problem in layout?

Hi,

You can use in fingers as well as multipliers by dividing the total width

Examples:
Total width =75um.
Make W=5um, Fingers=15 ===> F=15, W/L=(5um/150n).
Make W=5um, Fingers=5 and Multiplier M =3 ===> M=3, F=5, W/L=(5um/150n).

Large number of fingers will not cause any problems.
You have to decide the no of Fingers and Multipliers based on the MATCHING, LAYOUT EFFECTS and TECH NODES.
These combinations will helpful in layout design and as well as for matching point.

regards,
Basu

 

[anindya1012]

Thanks Basu!