ST NE556/SA556/SE556 GENERAL PURPOSE DUAL BIPOLAR TIMERS Manual

The NE556 is a dual monolithic timing circuit that is highly stable and capable of producing accurate time delays or oscillation. It has features such as low turn off time, maximum operating frequency greater than 500kHz, timing from microseconds to hours, operates in both astable and monostable modes, high output current can source or sink 200mA, adjustable duty cycle, and TTL compatibility.