74LVC1G123GN,115

The 74LVC1G123 is a single retriggerable monostable multivibrator with Schmitt trigger inputs. Output pulse width is controlled by three methods: The basic pulse is programmed by selection of an external resistor (REXT) and capacitor (CEXT). 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. 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 V or 5 V devices. This feature allows the use of these devices as translators in a mixed 3.3 V and 5 V environment. Schmitt-trigger inputs, makes the circuit highly tolerant to slower input rise and fall times. This device is fully specified for partial power-down applications using IOFF. The IOFF circuitry disables the output, preventing the damaging backflow current through the device when it is powered down.