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SN54F621, SN74F621
OCTAL BUS TRANSCEIVERS
WITH OPEN-COLLECTOR OUTPUTS
SDFS004B – D2932, MARCH 1987 – REVISED OCTOBER 1993
•
•
•
Local Bus-Latch Capability
Noninverting Logic
Package Options Include Plastic
Small-Outline Packages, Ceramic Chip
Carriers, and Standard Plastic and Ceramic
300-mil DIPs
SN54F621 . . . J PACKAGE
SN74F621 . . . DW OR N PACKAGE
(TOP VIEW)
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
L
L
H
H
OEAB
L
H
L
H
OPERATION
B data to A bus
B data to A bus,
A data to B bus
Isolation
A data to B bus
OEAB
A1
A2
A3
A4
A5
A6
A7
A8
GND
1
2
3
4
5
6
7
8
9
10
20
19
18
17
16
15
14
13
12
11
V
CC
OEBA
B1
B2
B3
B4
B5
B6
B7
B8
SN54F621 . . . FK PACKAGE
(TOP VIEW)
A2
A1
OEAB
V
CC
A3
A4
A5
A6
A7
4
5
6
7
8
3 2 1 20 19
18
17
16
15
14
9 10 11 12 13
OEBA
B1
B2
B3
B4
B5
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.
Copyright
©
1993, Texas Instruments Incorporated
POST OFFICE BOX 655303
•
DALLAS, TEXAS 75265
A8
GND
B8
B7
B6
2–1
SN54F621, SN74F621
OCTAL BUS TRANSCEIVERS
WITH OPEN-COLLECTOR OUTPUTS
SDFS004B – D2932, MARCH 1987 – REVISED OCTOBER 1993
logic symbol
†
19
OEBA
OEAB
A1
1
2
EN1
EN2
1
2
18
B1
logic diagram (positive logic)
OEBA
OEAB
19
1
A2
A3
A4
A5
A6
A7
A8
3
4
5
6
7
8
9
17
16
15
14
13
12
11
B2
B3
B4
B5
B6
B7
B8
A1
2
18
B1
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
MIN
VCC
VIH
VOH
VIL
IIK
IOL
TA
Supply voltage
High-level input voltage
High-level output voltage
Low-level input voltage
Input clamp current
Low-level
Low level output current
Operating free-air temperature
A1 – A8
B1 – B8
– 55
4.5
2
5.5
0.8
– 18
20
48
125
0
NOM
5
MAX
5.5
SN74F621
MIN
4.5
2
5.5
0.8
– 18
24
64
70
NOM
5
MAX
5.5
UNIT
V
V
V
V
mA
mA
°C
2–2
POST OFFICE BOX 655303
•
DALLAS, TEXAS 75265
SN54F621, SN74F621
OCTAL BUS TRANSCEIVERS
WITH OPEN-COLLECTOR OUTPUTS
SDFS004B – D2932, MARCH 1987 – REVISED OCTOBER 1993
electrical characteristics over recommended operating free-air temperature range (unless
otherwise noted)
PARAMETER
VIK
IOH
A1 – A8
VOL
B1 – B8
II
IIH‡
IIL‡
A and B ports
OEAB or OEBA
A and B ports
OEAB or OEBA
A and B ports
OEAB or OEBA
VCC = 5 5 V
5.5
VCC = 5 5 V
5.5 V,
VCC = 5 5 V
5.5 V,
VCC = 4 5 V
4.5
VCC = 4.5 V,
VCC = 4.5 V,
TEST CONDITIONS
II = – 18 mA
VOH = 5.5 V
IOL = 20 mA
IOL = 24 mA
IOL = 48 mA
IOL = 64 mA
VI = 5.5 V
VI = 7 V
VI = 2 7 V
2.7
VI = 0 5 V
0.5
105
105
0.3
0.38
SN54F621
MIN TYP†
MAX
– 1.2
250
0.5
0.35
0.55
0.42
1
0.1
70
20
– 0.65
– 0.6
140
140
105
105
0.55
1
0.1
70
20
– 0.65
– 0.6
140
140
mA
µA
mA
mA
mA
0.5
V
SN74F621
MIN TYP†
MAX
– 1.2
250
UNIT
V
µA
ICCH
VCC = 5.5 V
ICCL
VCC = 5.5 V
† 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)
VCC = 5 V,
CL = 50 pF,
RL = 500
Ω,
TA = 25°C
′F621
MIN
tPLH
tPHL
tPLH
tPHL
tPLH
tPHL
tPLH
tPHL
A
B
B
A
A
B
6
2.5
6
2.5
6
3.5
7
3.5
TYP
9.5
3.8
9
4
10
6.5
12
6.5
MAX
12
8
12
7.5
13.5
10.5
15
9.5
VCC = 4.5 V to 5.5 V,
CL = 50 pF,
RL = 500
Ω,
TA = MIN to MAX§
SN54F621
MIN
5.5
2
5.5
2
5.5
2.5
6
3
MAX
13
8.5
12.5
8
14
11
17
10
SN74F621
MIN
5.5
2
5.5
2
5.5
2.5
6
3
MAX
13
8.5
12.5
8
14
11
17
10
ns
ns
ns
ns
PARAMETER
FROM
(INPUT)
TO
(OUTPUT)
UNIT
OEBA
OEAB
§ 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.
POST OFFICE BOX 655303
•
DALLAS, TEXAS 75265
2–3
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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