Saturating logic draws large fast current spikes from its supply during switching and, having noise immunity of hundreds of millivolts or more, has little need of high levels of supply decoupling.

• 晶体管在开关过程中会流过短暂的大电流（带来噪声），但是数字电路的噪声容限可达数百毫伏，所以对电源去耦的要求不高。