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:
“Poetry is above all a concentration of the power of language, which is the power of our ultimate relationship to everything in the universe.”
—Adrienne Rich (b. 1929)
“The Landlord is a gentleman ... who does not earn his wealth. He has a host of agents and clerks that receive for him. He does not even take the trouble to spend his wealth. He has a host of people around him to do the actual spending. He never sees it until he comes to enjoy it. His sole function, his chief pride, is the stately consumption of wealth produced by others.”
—David Lloyd George (1863–1945)