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HD74LV221A
Dual Monostable Multivibrators
ADE-205-271A (Z) 2nd Edition June 1999 Description
The HD74LV221A 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 basic pulse duration is programmed 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. Pulse duration can be reduced by taking CLR low.
HD74LV221A Datasheet
