Texas Instruments SN74ABT821ADBLE, SN74ABT821ADBR, SN74ABT821ADW, SN74ABT821ADWR, SN74ABT821ANT Datasheet

SN54ABT821, SN74ABT821A

10-BIT BUS-INTERFACE FLIP-FLOPS

WITH 3-STATE OUTPUTS

SCBS193E – FEBRUARY 1991 – REVISED MAY 1997

1

POST OFFICE BOX 655303 • DALLAS, TEXAS 75265

D

State-of-the-Art

EPIC-ΙΙB

 BiCMOS Design

Significantly Reduces Power Dissipation

D

ESD Protection Exceeds 2000 V Per
MIL-STD-883, Method 3015

D

Latch-Up Performance Exceeds 500 mA Per
JEDEC Standard JESD-17

D

T ypical V

OLP

(Output Ground Bounce) < 1 V

at VCC = 5 V, TA = 25°C

D

High-Impedance State During Power Up
and Power Down

D

High-Drive Outputs (–32-mA IOH, 64-mA IOL)

D

Package Options Include Plastic
Small-Outline (DW) and Shrink
Small-Outline (DB) Packages, Ceramic Chip
Carriers (FK), Ceramic Flat (W) Package,
and Plastic (NT) and Ceramic (JT) DIPs

description

These 10-bit 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 ten flip-flops are edge-triggered D-type
flip-flops. On the positive transition of the clock
(CLK) input, the devices provide true data at the
Q outputs.

A buffered output-enable (OE) input can be used
to place the ten 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 drive provide the capability to drive bus
lines without need for interface or pullup
components.

OE

does not affect the internal operations of the latch. Previously stored data can be retained or new data can

be entered while the outputs are in the high-impedance state.
When VCC is between 0 and 2.1 V , the device is in the high-impedance state during power up or power down.

However, to ensure the high-impedance state above 2.1 V, OE should be tied to VCC through a pullup resistor;
the minimum value of the resistor is determined by the current-sinking capability of the driver.

The SN54ABT821 is characterized for operation over the full military temperature range of –55°C to 125°C. The
SN74ABT821A is characterized for operation from –40°C to 85°C.

Copyright  1997, Texas Instruments Incorporated

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.

Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of
Texas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.

EPIC-ΙΙB is a trademark of Texas Instruments Incorporated.

SN54ABT821 . . . JT OR W PACKAGE

SN74ABT821A . . . DB, DW, OR NT PACKAGE

(TOP VIEW)

SN54ABT821 . . . FK PACKAGE

(TOP VIEW)

1
2
3
4
5
6
7
8
9
10
11
12

24
23
22
21
20
19
18
17
16
15
14
13

OE

1D
2D
3D
4D
5D
6D
7D
8D
9D

10D

GND

V

CC

1Q
2Q
3Q
4Q
5Q
6Q
7Q
8Q
9Q
10Q
CLK

3212827

12 13

5
6
7
8
9
10
11

25
24
23
22
21
20
19

3Q
4Q
5Q
NC
6Q
7Q
8Q

3D
4D
5D

NC

6D
7D
8D

426

14 15 16 17 18

9D

10D

GND

NC

CLK

10Q

9Q

2D1DOE

NC

1Q

2Q

V

CC

NC – No internal connection

SN54ABT821, SN74ABT821A
10-BIT BUS-INTERFACE FLIP-FLOPS
WITH 3-STATE OUTPUTS

SCBS193E – FEBRUARY 1991 – REVISED MAY 1997

2

POST OFFICE BOX 655303 • DALLAS, TEXAS 75265

FUNCTION TABLE

(each flip-flop)

INPUTS

OUTPUT

OE CLK D

Q

L ↑ H H
L ↑ LL
L H or L X Q

0

H X X Z

logic symbol

†

6Q

18

7Q

17

8Q

16

9Q

15

10Q

14

7

6D

8

7D

9

8D

10

9D

EN

1

1Q

23

3

2D

4

3D

5

4D

6

5D

2Q

22

3Q

21

4Q

20

5Q

19

13

CLK

OE

11

10D

C2

2D

2

1D

†

This symbol is in accordance with ANSI/IEEE Std 91-1984 and IEC Publication 617-12.

Pin numbers shown are for the DB, DW, JT, NT, and W packages.

logic diagram (positive logic)

1D

OE

1Q

CLK

To Nine Other Channels

C1

1D

1

13

2

23

Pin numbers shown are for the DB, DW, JT, NT, and W packages.

SN54ABT821, SN74ABT821A

10-BIT BUS-INTERFACE FLIP-FLOPS

WITH 3-STATE OUTPUTS

SCBS193E – FEBRUARY 1991 – REVISED MAY 1997

3

POST OFFICE BOX 655303 • DALLAS, TEXAS 75265

absolute maximum ratings over operating free-air temperature range (unless otherwise noted)

†

Supply voltage range, V

CC

–0.5 V to 7 V. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Input voltage range, VI (see Note 1) –0.5 V to 7 V. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Voltage range applied to any output in the high or power-off state, VO –0.5 V to 5.5 V. . . . . . . . . . . . . . . . . . .

Current into any output in the low state, IO: SN54ABT821 96 mA. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

SN74ABT821A 128 mA. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Input clamp current, I

IK

(VI < 0) –18 mA. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Output clamp current, IOK (VO < 0) –50 mA. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Package thermal impedance, θ

JA

(see Note 2): DB package 104°C/W. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

DW package 81°C/W. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

NT package 67°C/W. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Storage temperature range, T

stg

–65°C to 150°C. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

†

Stresses beyond those listed under “absolute maximum ratings” may cause permanent damage to the device. These are stress ratings only, and
functional operation of the device at these or any other conditions beyond those indicated under “recommended operating conditions” is not
implied. Exposure to absolute-maximum-rated conditions for extended periods may affect device reliability.

NOTES: 1. The input and output negative-voltage ratings may be exceeded if the input and output clamp-current ratings are observed.

2. The package thermal impedance is calculated in accordance with EIA/JEDEC Std JESD51, except for through-hole packages,
which use a trace length of zero.

recommended operating conditions (see Note 3)

SN54ABT821 SN74ABT821A

MIN MAX MIN MAX

UNIT

V

CC

Supply voltage 4.5 5.5 4.5 5.5 V

V

IH

High-level input voltage 2 2 V

V

IL

Low-level input voltage 0.8 0.8 V

V

I

Input voltage 0 V

CC

0 V

CC

V

I

OH

High-level output current –24 –32 mA

I

OL

Low-level output current 48 64 mA

∆t/∆v Input transition rise or fall rate 10 10 ns/V
∆t/∆V

CC

Power-up ramp rate 200 200 µs/V

T

A

Operating free-air temperature –55 125 –40 85 °C

NOTE 3: Unused inputs must be held high or low to prevent them from floating.