SN54ALS573C, SN54AS573A, SN74ALS573C, SN74AS573A

OCTAL D-TYPE TRANSPARENT LATCHES

WITH 3-STATE OUTPUTS

SDAS048D – DECEMBER 1989 – REVISED JANUARY 1995

Copyright

1

POST OFFICE BOX 655303

Lines Directly

Small-Outline (DW) Packages, Ceramic

Chip Carriers (FK), Standard Plastic (N) and

Ceramic (J) 300-mil DIPs, and Ceramic Flat

(W) Packages

description

These octal D-type transparent latches feature

3-state outputs designed specifically for driving

highly capacitive or relatively low-impedance

loads.

They

are

particularly

suitable

for

implementing

buffer

registers,

I/O

ports,

bidirectional bus drivers, and working registers.

While the latch-enable (LE) input is high, outputs

(Q) respond to the data (D) inputs. When LE is low,

the outputs are latched to retain the data that was

set up.

A buffered output-enable (OE) input can be used

to place the eight outputs in either a normal logic

state (high or low) or a high-impedance state. In

the high-impedance state, the outputs neither load

nor

drive

the

bus

lines

significantly.

The

high-impedance state and the increased drive

provide the capability to drive bus lines without

interface or pullup components.

OE does not affect internal operation of the

latches. Old data can be retained or new data can

be entered while the outputs are in the

high-impedance state.

The SN54ALS573C and SN54AS573A are characterized for operation over the full military temperature range

of – 55

°C to 125°C. The SN74ALS573C and SN74AS573A are characterized for operation from 0°C to 70°C.

FUNCTION TABLE

(each latch)

INPUTS

OUTPUT

OE

LE

D

Q

L

H

H

H

L

HL

L

L

LX

Q0

H

X

X

Z

1

2

3

4

5

6

7

8

9

10

20

19

18

17

16

15

14

13

12

11

OE

1D

2D

3D

4D

5D

6D

7D

8D

GND

1Q

2Q

3Q

4Q

5Q

6Q

7Q

8Q

LE

SN54ALS573C, SN54AS573A ...J OR W PACKAGE

SN74ALS573C, SN74AS573A . . . DW OR N PACKAGE

(TOP VIEW)

32 1 20 19

910 11 12 13

4

5

6

7

8

18

17

16

15

14

2Q

3Q

4Q

5Q

6Q

3D

4D

5D

6D

7D

SN54ALS573C, SN54AS573A . . . FK PACKAGE

(TOP VIEW)

PRODUCTION DATA information is current as of publication date.

Products conform to specifications per the terms of Texas Instruments

standard warranty. Production processing does not necessarily include

testing of all parameters.