The NE556 are Dual Precision timing circuits capable of producing accurate time delays or oscillation
Timing From Microseconds to Hours
Astable or Monostable Operation, TTL-Compatible Output Can Sink or Source Up to 200 mA
Adjustable Duty Cycle, On Products Compliant to MIL-PRF-38535,
Example Applications: Fingerprint Biometrics, Iris Biometrics, RFID Reader, Precision Timers From Microseconds to Hours, Pulse-Shaping Circuits, Missing-Pulse Detector, Tone-Burst Generators, Pulse-Width Modulators, Pulse-Position Modulators, Sequential Timers, Pulse Generators, Frequency Dividers, Application Timers, Industrial Controls, Touch-Tone Encoders and a slew of other use-cases