74LS221中文资料仙童半导体数据手册PDF规格书

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.

特性 Features

■A dual, highly stable one-shot

■Compensated for VCCand temperature variations

■Pin-out identical to DM74LS123 (Note 1)

■Output pulse width range from 30 ns to 70 seconds

■Hysteresis provided at (B) input for added noise immunity

■Direct reset terminates output pulse

■Triggerable from CLEAR input

■DTL, TTL compatible

■Input clamp diodes