[SOLVED] Fingers and Multiplier concept in schematic and Layout (CADENCE)

[kenambo]

Hi,

I found fingers and multiplier options available in schematic and layout....{cadence TOOL)

and i tested a MOS with 2 fingers and 2 multipliers ,, it shows similar results....

What is the difference Between fingers and multipliers?

Do these affect the characteristics of the MOS we use?

does this depend on pdk?

thanks to all...

 

[Yarrow]

Fingers: Two poly gates in a single transistor with a source and a drain terminal
Multiplier: Two transistors, each with a single poly gate and a source and a drain terminal

The setting has an effect on the MOS characteristics. For example the LOD (length of diffusion) effect. This effect will be visible when designing differential pairs and current mirrors, however I am not sure how well it is modeled from process to process.

 

[kenambo]

yes ofcourse ... but when i am doing layout, i can just take 2 moses and overlap both drain regions and short circuit two sources & two gates....
like S G D G S...

then this is same as mos with 2 fingers .. or any difference between this and mos with 2 fingers...

thanks for ur reply...

 

[erikl]

S G D G S... then this is same as mos with 2 fingers

Yes!

.. or any difference between this and mos with 2 fingers...

No!

With the multiplier you create multiple equal devices of the same type (fingered or non-fingered).