DESCRIPTION NE555P

The 555 monolithic timing circuit is a highly stable controller capable
of producing accurate time delays, or oscillation. In the time delay
mode of operation, the time is precisely controlled by one external
resistor and capacitor. For a stable operation as an oscillator, the
free running frequency and the duty cycle are both accurately
controlled with two external resistors and one capacitor. The circuit
may be triggered and reset on falling waveforms, and the output
structure can source or sink up to 200mA.