SN54ALS563B, SN74ALS563B

OCTAL D-TYPE TRANSPARENT LATCHES

WITH 3-STATE OUTPUTS

SDAS163A – DECEMBER 1982 – 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 8-bit 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, the Q

outputs follow the complements of data (D) inputs.

When LE is taken low, the outputs are latched at

the inverses of the levels set up at the D inputs.

A buffered output-enable (OE) input places the

eight outputs in either a normal logic state (high or

low logic levels) 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 increased high logic

level provide the capability to drive bus lines

without interface or pullup components.

OE does not affect internal operations of the latches. Old data can be retained or new data can be entered while

the outputs are in the high-impedance state.

The SN54ALS563B is characterized for operation over the full military temperature range of – 55

°C to 125°C.

The SN74ALS563B is characterized for operation from 0

°C to 70°C.

FUNCTION TABLE

(each latch)

INPUTS

OUTPUT

OE

LE

D

Q

L

H

H

L

L

HH

H

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

SN54ALS563B ...J OR W PACKAGE

SN74ALS563B . . . 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

SN54ALS563B . . . 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.