However, it has not been possible to scale the supply voltage used to operate these ICs proportionately due to factors such as compatibility with previous generation circuits, noise margin, power and delay requirements, and non-scaling of threshold voltage, subthreshold slope, and parasitic capacitance.
12.
We've probably all done it ( a classic example is making a one-shot out of a Schmitt inverter, capacitor and diode ) but they eat into your noise margins and change behaviour with temperature . " There's a textbook with a chapter about it here.
13.
The noise margin-the amount of noise required to cause the receiver to get an error-is given by the distance between the signal and the zero amplitude point at the sampling time; in other words, the further from zero at the sampling time the signal is the better.
14.
With the advent of CMOS, the precharge transistor could be changed to be the complement of the logic transistor type, which allows the gate's output to charge quickly all the way up to the high level of the clock line, thus improving the speed, signal swing, power consumption, and noise margin.
15.
The input source has to be low-resistive enough ( < 500 ? ) so that the flowing current creates only a negligible voltage drop ( < 0.4 V ) across it, for the input to be considered as a logical " 0 " ( with a 0.4 V " noise margin ", see below ).
