SN74LV123AD

The SN74LV123AD is a dual retriggerable Monostable Multivibrator designed for 2 to 5.5V VCC operation. It features output pulse-duration control by three methods. In the first method, the A input is low and the B input goes high. In the second method, the B input is high and the A\ input goes low. In the third method, the A\ input is low, the B input is high and the clear (CLR/) input goes high. The output pulse duration is programmable by selecting external resistance and capacitance values. The external timing capacitor must be connected between Cext and Rext/Cext (positive) and an external resistor connected between Rext/Cext and VCC. To obtain variable pulse durations, connect an external variable resistance between Rext/Cext and VCC. The output pulse duration also can be reduced by taking CLR\ low.