The MM74HC574 high speed octal D-type flip-flops utilize
advanced silicon-gate P-well CMOS technology. They possess the high noise immunity and low power consumption
of standard CMOS integrated circuits, as well as the ability
to drive 15 LS-TTL loads. Due to the large output drive
capability and the 3-STATE feature, these devices are ideally suited for interfacing with bus lines in a bus organized
system.
These devices are positive edge triggered flip-flops. Data
at the D inputs, meeting the set-up and hold time requirements, are transferred to the Q outputs on positive going
transitions of the CLOCK (CK) input. When a high logic
level is applied to the OUTPUT CONTROL (OC) input, all
outputs go to a high impedance state, regardless of what
signals are present at the other inputs and the state of the
storage elements.
The 74HC logic family is speed, function, and pinout compatible with the standard 74LS logic family. All inputs are
protected from damage due to static discharge by internal
diode clamps to VCC and ground.

Documents:

http://www.nxp.com/documents/data_sheet/74HC_HCT574.pdf