74LVC1G123DC,125

The 74LVC1G123DC is a single retriggerable Monostable Multivibrator with schmitt trigger inputs. Output pulse width is controlled by three methods, first - the basic pulse is programmed by selection of an external resistor (REXT) and capacitor (CEXT). Second - once triggered, the basic output pulse width may be extended by retriggering the gated active low-going edge input (A) or the active high-going edge input (B). By repeating this process, the output pulse period (Q = high) can be made as long as desired. Alternatively an output delay can be terminated at any time by a low-going edge on input CLR, which also inhibits the triggering. Third, an internal connection from CLR to the input gates makes it possible to trigger the circuit by a high-going signal at input CLR. Inputs can be driven from either 3.3 or 5V devices. This feature allows the use of these devices as translators in a mixed 3.3 and 5V environment.