Datasheet SN54F621J Datasheet (Texas Instruments)

SN54F621, SN74F621

OCTAL BUS TRANSCEIVERS

WITH OPEN-COLLECTOR OUTPUTS

SDFS004B – D2932, MARCH 1987 – REVISED OCTOBER 1993

Copyright  1993, Texas Instruments Incorporated

2–1

POST OFFICE BOX 655303 • DALLAS, TEXAS 75265

• Local Bus-Latch Capability

• Noninverting Logic

• Package Options Include Plastic

Small-Outline Packages, Ceramic Chip
Carriers, and Standard Plastic and Ceramic
300-mil DIPs

description

These octal bus transceivers are designed for
asynchronous communication between data
buses. The control function implementation allows
for maximum flexibility in timing.

These devices allow data transmission from the A
bus to the B bus or from the B bus to the A bus
depending upon the logic levels at the output
enable (OEAB and OEBA

) inputs.

The output-enable inputs can be used to disable
the device so that the buses are effectively
isolated. The dual-enable configuration gives the
transceivers the capability of storing data by
simultaneously enabling OEAB and OEBA

. Each
output reinforces its input in this configuration.
When both OEAB and OEBA

are enabled and all
other data sources to the two sets of bus lines are
at high impedance, both sets of bus lines (16 in all)
will remain at their last states.

The SN54F621 is characterized for operation over
the full military temperature range of –55°C to
125°C. The SN74F621 is characterized for
operation from 0°C to 70°C.

FUNCTION TABLE

INPUTS

OEBA OEAB

OPERATION

L L B data to A bus
L H

B data to A bus,

A data to B bus
H L Isolation
H H A data to B bus

1
2
3
4
5
6
7
8
9
10

20
19
18
17
16
15
14
13
12
11

OEAB

A1
A2
A3
A4
A5
A6
A7
A8

GND

V

CC

OEBA
B1
B2
B3
B4
B5
B6
B7
B8

SN54F621 ...J PACKAGE

SN74F621 . . . DW OR N PACKAGE

(TOP VIEW)

3 2 1 20 19

9 10 11 12 13

4
5
6
7
8

18
17
16
15
14

B1
B2
B3
B4
B5

A3
A4
A5
A6
A7

SN54F621 . . . FK PACKAGE

(TOP VIEW)

A2A1OEAB

B7

B6

OEBA

A8

GND

B8

V

CC

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.

SN54F621, SN74F621
OCTAL BUS TRANSCEIVERS
WITH OPEN-COLLECTOR OUTPUTS

SDFS004B – D2932, MARCH 1987 – REVISED OCTOBER 1993

2–2

POST OFFICE BOX 655303 • DALLAS, TEXAS 75265

logic symbol

†

logic diagram (positive logic)

2

A1 B1

EN1

19

EN2

1

OEAB

2

A1

3

A2

B1

18

4

A3

5

A4

6

A5

7

A6

8

A7

9

A8

B2

17

B3

16

B5

14

B4

15

B6

13

B8

11

B7

12

OEBA

1

OEBA

OEAB

19

1

182

To Seven Other Channels

†

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

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, V

I

(excluding I/O ports) (see Note 1) –1.2 V to 7 V. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Input current range, I

IK

–30 mA to 5 mA. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Voltage range applied to any output in the high state –0.5 V to 5.5 V. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Current into any output in the low state: SN54F621 (A1–A8) 40 mA. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

SN54F621 (B1–B8) 96 mA. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

SN74F621 (A1–A8) 48 mA. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

SN74F621 (B1–B8) 128 mA. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Operating free-air temperature range: SN54F621 –55°C to 125°C. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

SN74F621 0°C to 70°C. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Storage temperature range –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.

NOTE 1: The input-voltage ratings may be exceeded provided the input-current ratings are observed.

recommended operating conditions

SN54F621 SN74F621

MIN NOM MAX MIN NOM MAX

UNIT

V

CC

Supply voltage 4.5 5 5.5 4.5 5 5.5 V

V

IH

High-level input voltage 2 2 V

V

OH

High-level output voltage 5.5 5.5 V

V

IL

Low-level input voltage 0.8 0.8 V

I

IK

Input clamp current –18 –18 mA

p

A1–A8 20 24

IOLLow-level output current

B1–B8 48 64

mA

T

A

Operating free-air temperature –55 125 0 70 °C

SN54F621, SN74F621

OCTAL BUS TRANSCEIVERS

WITH OPEN-COLLECTOR OUTPUTS

SDFS004B – D2932, MARCH 1987 – REVISED OCTOBER 1993

2–3

POST OFFICE BOX 655303 • DALLAS, TEXAS 75265

electrical characteristics over recommended operating free-air temperature range (unless
otherwise noted)

SN54F621 SN74F621

PARAMETER

TEST CONDITIONS

MIN TYP†MAX MIN TYP†MAX

UNIT

V

IK

VCC = 4.5 V, II = – 18 mA – 1.2 – 1.2 V

I

OH

VCC = 4.5 V, VOH = 5.5 V 250 250 µA

IOL = 20 mA 0.3 0.5

A1–A8

IOL = 24 mA 0.35 0.5

VOLV

CC

= 4.5

V

IOL = 48 mA 0.38 0.55

V

B1–B8

IOL = 64 mA 0.42 0.55

A and B ports

VI = 5.5 V 1 1

I

I

OEAB or OEBA

V

CC

=

5.5 V

VI = 7 V 0.1 0.1

mA

A and B ports

70 70

I

IH

‡

OEAB or OEBA

V

CC

= 5.5 V,

V

I

= 2.7

V

20 20

µ

A

A and B ports

– 0.65 – 0.65

I

IL

‡

OEAB or OEBA

V

CC

= 5.5 V,

V

I

= 0.5

V

–0.6 – 0.6

mA

I

CCH

VCC = 5.5 V 105 140 105 140 mA

I

CCL

VCC = 5.5 V 105 140 105 140 mA

†

All typical values are at VCC = 5 V, TA = 25°C.

‡

For I/O ports, the parameters IIH and IIL include the off-state output current.

switching characteristics (see Note 2)

PARAMETER

FROM

(

INPUT

)

TO

(

OUTPUT

)

VCC = 5 V,
CL = 50 pF,
RL = 500 Ω,
TA = 25°C

VCC = 4.5 V to 5.5 V,
CL = 50 pF,
RL = 500Ω,
TA = MIN to MAX

§

UNIT

(INPUT)

(OUTPUT)

′F621 SN54F621 SN74F621

MIN TYP MAX MIN MAX MIN MAX

t

PLH

6 9.5 12 5.5 13 5.5 13

t

PHL

A

B

2.5 3.8 8 2 8.5 2 8.5

ns

t

PLH

6 9 12 5.5 12.5 5.5 12.5

t

PHL

B

A

2.5 4 7.5 2 8 2 8

ns

t

PLH

6 10 13.5 5.5 14 5.5 14

t

PHL

OEBA

A

3.5 6.5 10.5 2.5 11 2.5 11

ns

t

PLH

7 12 15 6 17 6 17

t

PHL

OEAB

B

3.5 6.5 9.5 3 10 3 10

ns

§

For conditions shown as MIN or MAX, use the appropriate value specified under recommended operating conditions.

NOTE 2: Load circuits and waveforms are shown in Section 1.

SN54F621, SN74F621
OCTAL BUS TRANSCEIVERS
WITH OPEN-COLLECTOR OUTPUTS

SDFS004B – D2932, MARCH 1987 – REVISED OCTOBER 1993

2–4

POST OFFICE BOX 655303 • DALLAS, TEXAS 75265

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