DM74LS221

DM74LS221 Dual Non-Retriggerable One-Shot with Clear and Complementary Outputs February 1992 DM74LS221 Dual Non-Retriggerable One-Shot with Clear and Complementary Outputs General Description The DM74LS221 is a dual monostable multivibrator with Schmitt-trigger input Each device has three inputs permitting the choice of either leading-edge or trailing-edge triggering Pin (A) is an active-low trigger transition input and pin (B) is an active-high transition Schmitt-trigger input that allows jitter free triggering for inputs with transition rates as slow as 1 volt second This provides the input with excellent noise immunity Additionally an internal latching circuit at the input stage also provides a high immunity to VCC noise The clear (CLR) input can terminate the output pulse at a predetermined time independent of the timing components This (CLR) input also serves as a trigger input when it is pulsed with a low level pulse transition ( ) To obtain the best and trouble free operation from this device please read operating rules as well as the NSC one-shot application notes carefully and observe recommendations Features Y A dual highly stable one-shot Y Compensated for VCC and temperature variations Y Pin-out identical to ’LS123 (Note 1) Y Output pulse width range from 30 ns to 70 seconds Y Hysteresis provided at (B) input for added noise immunity Y Direct reset terminates output pulse Y Triggerable from CLEAR input Y DTL TTL compatible Y Input clamp diodes Note 1 The pin-o...