The MM54C221 MM74C221 dual monostable multivibrator is a monolithic complementary MOS integrated circuit Each multivibrator features a negative-transition-triggered input and a positive-transition-triggered input either of which can be used as an inhibit input and a clear input Once fired the output pulses are independent of further transitions of the A and B inputs and are a function of the external timing components CEXT and REXT The pulse width is stable over a wide range of temperature and VCC