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IC6 constraining/placing matched transistors

stuso

Hi there,

Is anyone aware if its possible to constrain the placement of transistors for matching such that you can dictate the order of devices and the layer used to space them.

For example i have a schematic with 3 mos device, all of same w/L and 1 finger and 2 multiples.

Schematic:

nm1 m(multiple)=2, nm2 m=2 , dummy1 m=2

I want layout to place/constrain these to align and equally space as:

dummy1.1    nm2.1     nm1.1     nm1.2    nm2.2     dummy1.2

so for example there is polygon in each pcell called OD which i would like NOT to overlap AND be spaced by 1um, so the layout looks like 6 transistors in a line with the OD layers spaced by 1um.

Its basiaclly a simple current mirror with nm1 the bias device in the centre, nm2 split either side & dummy on either end. For matching all 6 units are equally spaced.

Thanks

Stu

 

Parents

  •  Hi Sarvasti,

    i just happened across the modgen function last night, this is exactly what i need....it sounds like something we would use all the time.

    I only spent half an hour playing around with it but i couldn't quite get it to work yet. I you have time to provide a quick explanation of a simple example (like 3 transistors in a row) i'd really appreciate that. In the meantime i'll keep reading  the manual and messing with the modgen. I'm also interested to know if modgen can handle multiple transistors or does it prefer if you multiply transistors up by doing:

    nm1<0:1> (as opposed to nm1 with m=2)

    Thanks for your reply

    Stu

     

     

     

     

     

Reply

  •  Hi Sarvasti,

    i just happened across the modgen function last night, this is exactly what i need....it sounds like something we would use all the time.

    I only spent half an hour playing around with it but i couldn't quite get it to work yet. I you have time to provide a quick explanation of a simple example (like 3 transistors in a row) i'd really appreciate that. In the meantime i'll keep reading  the manual and messing with the modgen. I'm also interested to know if modgen can handle multiple transistors or does it prefer if you multiply transistors up by doing:

    nm1<0:1> (as opposed to nm1 with m=2)

    Thanks for your reply

    Stu

     

     

     

     

     

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