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Fingers and multiplier of MOSFET Last post Fri, Apr 12 2013 1:13 AM by Gangadhar Redd. 4 replies.

Started by jun1119 27 Oct 2010 05:43 AM. Topic has 4 replies and 10088 views

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jun1119

Joined on Tue, Jan 27 2009Posts 7

Points 140

Fingers and multiplier of MOSFET

Hi

What is the meaning of finger and multiplier in a MOSFET as we can see in the properties of a MOSFET?

I would highly appreciated if there are some diagrams and layout to be shown.

Thank you

Post Points: 35

Wed, Oct 27 2010 6:30 AM

baenisch Re: Fingers and multiplier of MOSFET

Hi there

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Joined on Mon, Oct 18 2010Posts 9

Points 135

I have no idea what the multiplier does, in fact if have never used this at all in 16 years.

The finger parameter on the other hand is very helpful if you want to draw big transistors.

Changing the finger parameter simply creates parallel transistor gates to exactly the amount you

have entered. Image you have a device in the schematic 400u wide but you don't have 400u

of space in either direction but you have a nice little rectangular spot left. You create a single

transistor 20u wide and change the finger parameter to 20. This yields in a 400u transistor

with 20 "fingers" a 20u, drain/source areas already merged. You just have to do the wiring.Simply try it !

Best Regards

Andi

Post Points: 20

Thu, Oct 28 2010 4:56 AM

berndf

Joined on Tue, Aug 25 2009Landshut, Bavaria

Posts 54Points 840

Re: Fingers and multiplier of MOSFET

This depends in the implementation of these parameters

In most cases I have seen- number of fingers is a pysical paramter which lets you fold your mos width a long with to several mos with width/finger and shared S/D areas.- the m is a multiplication factor for the simulator which multiplies the current though the devices.

Bernd

Post Points: 20


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Mon, Nov 1 2010 12:38 PM

vvacad

Joined on Wed, Jul 16 2008Posts 4

Points 35


Hi,

The m is the multiplication factor.

In Layout XL, for transistors, the m from the schematic is used to create multiple layout instances with commonparameters.

i.e. for eg., a schematic instance M0 with total_width=6u, length=1u, fingers=3 finger_width=2u m=5

will result in 5 layout instances:

M0.0: total_width=6u, length=1u, fingers=3 finger_width=2u





Rgds,

Vikram

Post Points: 5

Fri, Apr 12 2013 1:13 AM

Gangadhar Redd

Joined on Thu, Nov 29 2012


Multiplier - number of Parallel MOS devices

Finger Width - width of each gate finger/stripe


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Hyderabad, Andhra PradeshPosts 3

Points 30

Fingers - number of poly gate fingers/stripes used in layout

Thanks & Regards Gangadhar.R

Post Points: 5

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Started by jun1119 at 27 Oct 2010 05:43 AM. Topic has 4 replies.


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