The M74HC123 is an high speed CMOS MONOSTABLE MULTIVIBRATOR fabricated with silicon gate C2MOS technology. There are two trigger inputs, A INPUT (negative edge) and B INPUT (positive edge). These inputs are valid for slow rising/falling signals, (tr=tf=l sec). The device may also be triggered by using the CLR input (positive-edge) because of the Schmitt-trigger input; after triggering the output maintains the MONOSTABLE state for the time period determined by the external resistor Rx and capacitor Cx. When Cx > 10nF and Rx > 10KΩ, the output pulse width value is approsimatively given by the formula : tW(OUT) = K · Cx · Rx.