Texas Instruments SN74LS123

these d-c triggered multivibrators feature output pulse-duration control by three methods. the basic pulse time is programmed by selection of external resistance and capacitance values (see typical application data). the 122 and ls122 have 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. figure 1 illustrates pulse control by retriggering and early clear. the ls122 and ls123 are provided enough schmitt hysteresis to ensure jitter-free triggering from the b input with transition rates as slow as 0. view all in datasheet