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how miminum length should I used? (Read 2080 times)
Robert
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Xiamen city,Fujian PRO. china
how miminum length should I used?
May 31st, 2007, 3:03am
 
hi, all!
   i am designing a folded cascode OTA used in a LDO, to achive a acceptable offset caused by the transistor's mismatch, how miminum length of the input and load transistors should I used, my design is based on the Charter 0.35um CMOS process.  please give me any suggestions from your tapeout experience, thanks a lot!

best regards,
Robert
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krishnap
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Re: how miminum length should I used?
Reply #1 - May 31st, 2007, 3:44am
 
Hi  Robert,

Usual practise is to keep minimum design length to be 2 to 3 times that of process node.
In this case 2-3*0.35um

Regards,
Krishna
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Berti
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Re: how miminum length should I used?
Reply #2 - Jun 4th, 2007, 12:20am
 
Hello Robert,

I think this depends on the offset you can tolerate.
For applications where offset isn't the major concern, but
speed is important I usually use minimum length transistors
to take full advantage of the technology.

If offset is important but speed moderate I agree with Krishna
not to use minimum design length.

Cheers,

Thomas
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