The NE555 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.
The ST Micro SA555N is an 8 pin timer with industrial temperature and plastic DIP package.