DM74LS221 Datasheet | Fairchild Semiconductor

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 ponents. 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 remendations. Features s A dual, highly stable one-shot s pensated 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 patible s Input clamp diodes Note 1: The pin-out is identical to DM74LS123 but, functionally it is not; refer to Operating Rules #10 in this datasheet. Ordering Code: Order Number DM74LS221M DM74LS221SJ DM74LS221N Package Number M16A M16D N16E Package Description 16-Lead Small Outline Integrated Circuit (SOIC), JEDEC MS-012, 0.150 Narrow 16-Lead Small Outline Package (SOP), EIAJ TYPE II, 5.3mm Wide 16-Lead Plastic Dual-In-Line Package (PDIP), JEDEC MS-001, 0.300 Wide Devices also available in Tape and Reel. Specify by appending the suffix letter “X” to the ordering code. Connection Diagram Function Table Inputs CLEAR L X X H H ↑ (Note 2) A X H X L ↓ L B X X L ↑ H H Q L L Outputs Q H H H =...