SN74LS123N (TEXAS INSTRUMENTS)

The SN74LS123N is a dual retriggerable monostable Multi-vibrator features output pulse-duration control by three methods. The basic pulse time is programmed by selection of external resistance and capacitance values. It has an internal timing resistors that allow the circuits to be used with only an external capacitor, if so desired. Once triggered, the basic pulse duration may be extended by retriggering the gated low-level-active (A) or high-level-active (B) inputs or be reduced by use of the overriding clear. The LS123 are provided enough Schmitt hysteresis to ensure jitter-free triggering from the B-input with transition rates as slow as 0.1millivolt per nanosecond.