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Is 1k ohm for an on-chip resistor a large value?

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analog2003

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resistor chip

Hi all

I am implementing an op amp application in cmos 0.18um (thick oxide) technology. This application has about 7 resistors. Is 1k ohm for an on-chip resistor a large value? How do I know the maximum value for an on-chip resistor?

Any kind of help is highly appreciated. Thanks.
 

deepak242003

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large onchip resistance

Hi analog2003,

can you make your question more precise..??
Is it in terms of area...?? then it depends on what is the available area.... and precision your are looking......
I dont believe 1k is large value for on chip resistor......
 

DZC

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on chip resistance

Generally speaking, there's high poly resistor (r***_sab) available. Their sheet resistor are about 1Know Ohm/square. Then hundreds of K Ohm will be reasonable.
All in all, you have to check the sheet resistance of all the resistors available first.
 

tdy

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chip resistance

no
 

deepak242003

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chip resistor sheet resistance calculation

DZC is correct.
 

analog2003

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Re: on-chip resistance

Yes, I read about the different kinds of resistors available and seem to have a better understanding of this topic now. and so understand that 1k ohm is not a huge resistance.
I am using 3.3V devices in the CMOS 0.18um technology, which is a single poly process. Considering that I am making Poly resistors, where should I look up for the sheet resistance of the poly? I believe it depends on the strength of doping.

Thanks all for the help.
 

erikl

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Re: on-chip resistance

analog2003 said:
... where should I look up the sheet resistance of the poly?
In the manual or user guide of your PDK.

analog2003 said:
I believe it depends on the strength of doping.
Right. And (a lot more) on polycide usage or blanking.
 

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