Static Power Consumption
Depletion-load circuits consume less power than enhancement-load circuits at the same speed. In both cases the connection to 1 is always active, even when the connection to 0 is also active. This results in high static power consumption. The amount of waste depends on the strength, or physical size, of the pull-up. Both normal (enhancement-mode) and depletion-mode pull-up transistors use greatest power when the output is stable at 0, so this loss is considerable. The sizes of the pull-ups are thus adjusted so that the 0 to 1 transition speed matches the 1 to 0 speed, but no more, as that would waste power. Because the strength of a depletion-mode transistor falls off less on the approach to 1, they may reach 1 faster despite starting slower, i.e. conducting less current at the beginning of the transition and at steady state.
Read more about this topic: Depletion-load NMOS Logic
Famous quotes containing the words power and/or consumption:
“So immense are the claims on a mother, physical claims on her bodily and brain vigor, and moral claims on her heart and thoughts, that she cannot ... meet them all and find any large margin beyond for other cares and work. She serves the community in the very best and highest way it is possible to do, by giving birth to healthy children, whose physical strength has not been defrauded, and to whose moral and mental nature she can give the whole of her thoughts.”
—Frances Power Cobbe (1822–1904)
“Books constitute capital. A library book lasts as long as a house, for hundreds of years. It is not, then, an article of mere consumption but fairly of capital, and often in the case of professional men, setting out in life, it is their only capital.”
—Thomas Jefferson (1743–1826)