The Texas Instruments (TI) SN54/74LS123 dual retriggerable monostable multivibrator is a one-shot device capable of verylong output pulses and up to 100% duty cycle. The ?LS123 also features dc triggering from gated low-level active A andhigh-level active B inputs and provides a clear input that terminates the output pulse of any predetermined time independentof timing components R ext and