74LS74 pdf datasheet

54LS74/DM54LS74A/DM74LS74A
Dual Positive-Edge-Triggered D Flip-Flops
with Preset, Clear and Complementary Outputs
General Description
This device contains two independent positive-edge-triggered
D flip-flops with complementary outputs. The information
on the D input is accepted by the flip-flops on the positive
going edge of the clock pulse. The triggering occurs at a
voltage level and is not directly related to the transition time
of the rising edge of the clock. The data on the D input may
be changed while the clock is low or high without affecting
the outputs as long as the data setup and hold times are not
violated. A low logic level on the preset or clear inputs will
set or reset the outputs regardless of the logic levels of the
other inputs.
Features
Y Alternate military/aerospace device (54LS74) is available.
Contact a National Semiconductor Sales Office/
Distributor for specifications.