© 2000 Fairchild Semiconductor Corporation

DS006314

www.fairchildsemi.com

October 1986

Revised March 2000

DM74AS574

Octal D-Type Edge-Triggered Flip-Flops

with 3-STATE Outputs

General Description

These 8-bit registers feature totem-pole 3-STATE outputs

designed specifically for driving highly-capacitive or rela-

tively low-impedance loads. The high-impedance state and

increased HIGH-logic-level drive provide these registers

with the capability of being connected directly to and driv-

ing the bus lines in a bus-organized system without need

for interface or pull-up components. They are particularly

attractive for implementing buffer registers, I/O ports, bidi-

rectional bus drivers, and working registers.

The eight flip-flops of the DM74AS574 are edge-triggered

D-type flip-flops. On the positive transition of the clock, the

Q outputs will be set to the logic states that were set up at

the D inputs.

A buffered output control input can be used to place the

eight outputs in either a normal logic state (HIGH or LOW

logic levels) or a high impedance state. In the high-imped-

ance state the outputs neither load nor drive the bus lines

significantly.

The output control does not affect the internal operation of

the flip-flops. That is, the old data can be retained or new

data can be entered even while the outputs are OFF.

The pinout is arranged to ease printed circuit board layout.

All data inputs are on one side of the package while all the

outputs are on the other side.

Features

s Switching specifications at 50 pF

s Switching specifications guaranteed over full tempera-

s Advanced oxide-isolated, ion-implanted Schottky TTL

process

s Functionally equivalent with DM74S374

s Improved AC performance over DM74S374 at approxi-

mately half the power

s 3-STATE buffer-type outputs drive bus lines directly

s Bus structured pinout

Ordering Code:

Devices also available in Tape and Reel. Specify by appending the suffix letter “X” to the ordering code.

Connection Diagram

Order Number

Package Number

Package Description

DM74AS574WM

M20B

20-Lead Small Outline Integrated Circuit (SOIC), JEDEC MS-013, 0.300 Wide

DM74AS574N

N20A

20-Lead Plastic Dual-In-Line Package (PDIP), JEDEC MS-001, 0.300 Wide