The LV123A devices are dual retriggerable monostable multivibrators designed for 2-V to
5.5-V VCC operation.
These edge-triggered multivibrators feature 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