74LS123 Description
The DM74LS123 is a dual retriggerable monostable multivibrator capable of generating output pulses from a few nano-seconds to extremely long duration up to 100% duty cycle. Each device has three inputs permitting the choice of either leading edge or trailing edge triggering. Pin (A) is an active-LOW transition trigger input and pin (B) is an activeHIGH transition trigger input.