器件名称:
DM74LS221N
功能描述:
Dual Non-Retriggerable One-Shot with Clear and Complementary Outputs
文件大小:
108.95KB 共8页
简 介:
DM74LS221 Dual Non-Retriggerable One-Shot with Clear and Complementary Outputs August 1986 Revised April 2000 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 Fairchild Semiconductor one-shot application notes carefully and observe recommendations. Features s A dual, highly stable one-shot s Compensated for VCC and temperature variations s Pin-out identical to DM74LS123 (Note 1) s Output pulse width range from 30 ns to 70 seconds s Hysteresis provided at (B) input for added noise immunity s Direct reset terminates output pulse s Triggerable from CLEAR input s DTL, TTL……
