MOS device length in signal path

[kenambo]

Hi all,

why it is necessary to reduce the MOS length when it comes to signal path?

What are the advantage of reduced length devices in signal path.

example.. a simple differential receiver or a signal comparator..

the size of the receiveing differential pair MOS length is minimised and the width is maximised..

is there any paritcular reason for this..

thanks.

 

[dick_freebird]

gain (gm) goes as W/L. Up to some point, front end gain
is the most significant thing you can play with for low-
overdrive differential amplifier speed.