Fairchild Semiconductor DM74ALS580AWMX, DM74ALS580AWM, DM74ALS580AN Datasheet

© 2000 Fairchild Semiconductor Corporation DS006229 www.fairchildsemi.com

April 1984
Revised February 2000

DM74ALS580A Octal D-Type Transparent Latch with 3-STATE Outputs

DM74ALS580A
Octal D-Type Transparent Latch with 3-STATE Outputs

General Description

These 8-bit register s feature totem-pole 3- STATE outputs
designed specifically fo r driving highly-capacitive or rela­tively low-impedance loa ds. Th e hi gh -im ped ance state and
increased high-logic-level drive provide these registers with
the capability of being connected directly to and driving the
bus lines in a bu s-or ga nized sy stem w ith ou t n eed fo r inter­face or pull-up components. They are particularly attractive
for implementing buffer registers, I/O ports, bidirectional
bus drivers, and working registers.

The eight inverting latches of the DM74ALS580A are trans­parent D-type latches. While the e nable ( G) is HIGH th e Q
outputs will follow the complement of the data (D) inputs.
When the enable is taken LOW the output will be latched at
the complement of the level of the data that was set up.

A buffered output control input ca n be used to place the
eight outputs in either a normal l ogic state (HIGH or LOW
logic levels) or a high-impedance state. In the high-imped­ance state the outputs ne ither load nor dr ive the bus lines
significantly.

The output control does not affect the i nternal oper ation of
the latches. That is, the old data can be retained or new
data can be entered even while the outputs are OFF.

Features

■ Switching specifications at 50 pF

■ Switching specifications guaranteed over full tempera-

ture and V

CC

range

■ Advanced oxide-isolated, ion-implanted Schottky TTL
process

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

Ordering Code:

Devises also availab le in Tape and Reel. Specify by appending th e s uffix let t er “X” to the ordering code.

Connection Diagram

Order Number Package Number Package Description

DM74ALS580AWM M20B 20-Lead Small Outline Integrated Circuit (SOIC), JEDEC MS-013, 0.300 Wide
DM74ALS580AN N20A 20-Lead Plastic Dual-In-Line Package (PDIP), JEDEC MS-001, 0.300 Wide

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DM74ALS580A

Function Table

L = LOW State
H = HIGH State
X = Don’t Care
Z = High Impedance State
Q

0

= Previous Condit ion of Q

Logic Diagram

Output Enable D Output

Control G Q

LHHL
LHLH
LLXQ

0

HXXZ