74LS123 Monostable Multivibrator - (AD9122)

Description:

These multivibrators are characterized by having an output controlled by 3 methods, the basic time pulse is programmed by selecting values of an external resistor and capacitor. These have an internal timing resistor that allows the circuits to be used with only an external capacitor if desired. Once triggered, the basic pulse duration can be extended by setting the gate input A to LOW or input B to HIGH, or it can also be reduced.

Datasheet