Dual retriggerable monostable multivibrator with reset

The 74AHC123A; 74AHCT123A is a dual retriggerable monostable multivibrator with reset. The basic output pulse width is programmed by selection of external components (REXT and CEXT). Once triggered this basic pulse width may be extended by retriggering either of the edge triggered inputs (nA or (nB). By repeating this process, the output pulse period (nQ = HIGH, nQ = LOW) can be made as long as desired. Alternatively, an output delay can be terminated at any time by a LOW-going edge on input nRD. Inputs are overvoltage tolerant. This feature allows the use of these devices as translators in mixed voltage environments.