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Curious question about NMOS vs CMOS - why isn't NMOS capable of static operation

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alank2:
Curious question about NMOS vs CMOS - why isn't NMOS capable of static operation

coppice:
Nobody really makes NMOS chips any more, but most NMOS logic was static.

amyk:
It can be, but even in static state there will be significant power dissipation from the load "resistors".

David Hess:
A cursory search shows that NMOS, PMOS, and HMOS static devices were available.  Higher performance logic built on these processes often used dynamic logic for large combinatorial blocks as is the case with CMOS.

T3sl4co1l:
They didn't because it was hella inefficient and they took shortcuts wherever they possibly could -- i.e., dynamic gates.

The next generation (CMOS) used about the same area -- you need at least a transistor and resistor, for an NMOS gate cell -- but the resistors get replaced by PMOS, making it much more powerful.  There isn't anything wrong with making dynamic gates in CMOS still, but they probably used it as a selling point, or maybe there were, say, knock-on fab benefits that I'm not aware of.  The onward march to finer feature size helps too, although I don't know that, say, nearby generation NMOS and CMOS Z80s, were very different?

Tim

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