vieha007Electronic
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Hello,
I am designing circuit (using 0.18um). Usually, by biasing Vgs < Vthreshold of MOSFET, we can push MOS into sub-threshold region. My curious question is: How much value of Vgs is "good" as a "rule of thumb"?
I have referenced to "Trade-offs and optimization in Analog CMOS design" book, and they supplied a good reference (please check the figure below). It seems to be good from this book is that we should bias MOS
such that -4.5nUT < Vgs - Vth < -2nUT, which is equivalent to approximate value in a range of: -163 mV < Vgs - Vth < -72 mV (n is the slope factor defined by EKV model from EPFL, UT = kT/q is the thermal voltage).
Could you guys confirm or give out any recommendations?
Thank you!
I am designing circuit (using 0.18um). Usually, by biasing Vgs < Vthreshold of MOSFET, we can push MOS into sub-threshold region. My curious question is: How much value of Vgs is "good" as a "rule of thumb"?
I have referenced to "Trade-offs and optimization in Analog CMOS design" book, and they supplied a good reference (please check the figure below). It seems to be good from this book is that we should bias MOS
such that -4.5nUT < Vgs - Vth < -2nUT, which is equivalent to approximate value in a range of: -163 mV < Vgs - Vth < -72 mV (n is the slope factor defined by EKV model from EPFL, UT = kT/q is the thermal voltage).
Could you guys confirm or give out any recommendations?
Thank you!