GENERAL DESCRIPTION
Each multivibrator features both a negative, A, and a positive, B, transition triggered input, either of which can be used as an inhibit input. Also included is a clear input that when taken low resets the one shot. The MM74HC221A can be triggered on the positive transition of the clear while A is held LOW and B is held HIGH. The MM74HC221A is a non-retriggerable, and therefore cannot be retriggered until the output pulse times out. Pulse width stability over a wide range of temperature and supply is achieved using linear CMOS techniques. The output pulse equation is simply: PW = (REXT) (CEXT); where PW is in seconds, R is in ohms, and C is in farads. All inputs are protected from damage due to static discharge by diodes to VCC and ground. FEATURES
s Typical propagation delay: 40 ns s Wide power supply range: 2V–6V s Low quiescent current: 80 µA maximum (74HC Series) s Low input current: 1 µA maximum s Fanout of 10 LS-TTL loads s Simple pulse width formula T = RC s...
Fairchild Semiconductor
