kissmoh
Junior Member level 1
Why is the PMOS used for a output resistance of the current source, not NMOS?
Hi, I'm studying microelectronic circuits theory using sedra smith book.
The question is, this book is saying that in IC design, for load resistance, tr is used as a constant current source for some reasons and PMOS is usually used for it (im studying cascode amplifier circuit now and, if this will be help to understand what i meaning, this is written in ch. 6.2.1 and 6.2.3).
What is the reason to use PMOS(just as 'single' tr connected to drain node of the other NMOS which is for amplification) for constant current source as a load resistance in IC design, not NMOS?, is there any particular reason? (sorry for my poor english skill )
There were some comments saying that PMOS is usually used for constant current here and there, but i couldnt find the reason.
Hi, I'm studying microelectronic circuits theory using sedra smith book.
The question is, this book is saying that in IC design, for load resistance, tr is used as a constant current source for some reasons and PMOS is usually used for it (im studying cascode amplifier circuit now and, if this will be help to understand what i meaning, this is written in ch. 6.2.1 and 6.2.3).
What is the reason to use PMOS(just as 'single' tr connected to drain node of the other NMOS which is for amplification) for constant current source as a load resistance in IC design, not NMOS?, is there any particular reason? (sorry for my poor english skill )
There were some comments saying that PMOS is usually used for constant current here and there, but i couldnt find the reason.
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