NE555 is a common timer chip, its operating frequency is generally between tens of kHz to a few MHz, and its output frequency is also affected by external components. Although the operating frequency of the NE555 can theoretically reach 7MHz, in fact, due to the limitations of its internal structure and the parameters of external components, its output frequency is difficult to reach this range.
Therefore, the NE555 is usually used for the generation and processing of low-frequency signals, and for the generation and processing of high-frequency signals, more professional devices are required.