SN54BCT29825, SN74BCT29825

8BIT BUSINTERFACE FLIPFLOPS

WITH 3STATE OUTPUTS

SCBS075A − SEPTEMBER 1991 − REVISED NOVEMBER 1993

Copyright

2−1

POST OFFICE BOX 655303

POST OFFICE BOX 1443

MIL-STD-883C, Method 3015; Exceeds

200 V Using Machine Model (C = 200 pF,

R = 0)

Lines Directly

Small-Outline Packages (DW), Ceramic Chip

Carriers (FK) and Flatpacks (W), and

Standard Plastic and Ceramic 300-mil DIPs

(JT, NT)

description

These 8-bit bus-interface flip-flops feature 3-state

outputs designed specifically for driving highly

capacitive or relatively low-impedance loads.

They are particularly suitable for implementing

wider buffer registers, I/O ports, bidirectional bus

drivers with parity, and working registers.

The eight flip-flops are edge-triggered D-type

flip-flops. With the clock-enable (CLKEN) input

low, the device enters data on the low-to-high

transition of the clock. Taking CLKEN high

disables the clock buffer, thus latching the outputs.

Taking the clear (CLR) input low causes the eight

Q outputs to go low independently of the clock.

Buffered output-enable (OE1, OE2, or OE3)

inputs 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

increased drive provide the capability to drive bus

lines without need for interface or pullup

components.

The output-enable inputs do not affect the internal

operation of the flip-flops. Old data can be retained

or new data can be entered while the outputs are

in the high-impedance state.

The SN54BCT29825 is characterized for opera-

tion over the full military temperature range of

−55

°C to 125°C. The SN74BCT29825 is

characterized for operation from 0

°C to 70°C.

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6

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9

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12

24

23

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13

OE1

OE2

1D

2D

3D

4D

5D

6D

7D

8D

CLR

GND

OE3

1Q

2Q

3Q

4Q

5Q

6Q

7Q

8Q

CLKEN

CLK

SN54BCT29825 . . . JT OR W PACKAGE

SN74BCT29825 . . . DW OR NT PACKAGE

(TOP VIEW)

3 2

28 27

12 13

5

6

7

8

9

10

11

25

24

23

22

21

20

19

2Q

3Q

4Q

NC

5Q

6Q

7Q

2D

3D

4D

NC

5D

6D

7D

426

14 15 16 17 18

SN54BCT29825 . . . FK PACKAGE

(TOP VIEW)

NC − No internal connection

1

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.