Urgently,about subthreshold circuit design in CMOS process

[rficd]

ALL,
I meet a puzzle problem. In voltage follower design, I find many transistors in threshold region and the performance is good for large power supply variation. According to the general rule, the transistors should be in active region. I get the result that the performance is better while the transistor in subthreshold than that in active with the large power supply variation after I try many times.
maybe there is some magic. Please give me some pieces of advice on the problem.
Or someone can upload some design material about subthresold circuit design in CMOS process.
Is the subthresold circuit design is popular now in commercial CMOS IC design.
ALso, Is the subthreshold circuit robust while the power supply varies widely.

 

[pthoppay]

Re: Urgently,about subthreshold circuit design in CMOS proce

I really doubt your comment on better power supply regulation in sub-threshold region. Since, power supply noise rejection mainly depends on the output impedence of the MOSFET, and the output impedence is independent of the operating region and depends only on the bias current.

Sub-threshold or Weak inversion (W.I) operation is widely used in places where they need very low power consumption. typically in W.I region the MOSFETs are biased at 1uA, leading to very low power consumption.

Please try to find any paper by Prof. Eric Vittoz or Christain Enz to know more on Sub-threshold operation.


Prakash.

 

[szekit]

Re: Urgently,about subthreshold circuit design in CMOS proce

can you please post some papers from the authors?

 

[manish12]

Re: Urgently,about subthreshold circuit design in CMOS proce

Subthreshold region it looking to be good but in that region the transistor does not goes in to cutoff region in any condition which is the major problem for chip designer . Also this technology has a problem to interface with current technology .

 

[umagne]

Since February 2011 it'll be available on JSSC the design methodology of Subthreshold Voltage References, its DOI is 10.1109/JSSC.2010.2092997