SN54BCT25245, SN74BCT25245
25-Ω OCT AL BUS TRANSCEIVERS
WITH 3-STATE OUTPUTS
SCBS053B – MAY 1990 – REVISED APRIL 1994
Copyright 1994, Texas Instruments Incorporated
2–1
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
• State-of-the-Art BiCMOS Design
Significantly Reduces I
CCZ
• ESD Protection Exceeds 2000 V Per
MIL-STD-883C, Method 3015; Exceeds
200 V Using Machine Model (C = 200 pF,
R = 0)
• Designed to Facilitate Incident-Wave
Switching for Line Impedances of 25 Ω
or Greater
• Distributed V
CC
and GND Pins Minimize
Noise Generated by the Simultaneous
Switching of Outputs
• Package Options Include Plastic
Small-Outline (DW) Packages, Ceramic
Chip Carriers (FK) and Flatpacks (W), and
Standard Plastic and Ceramic 300-mil DIPs
(JT, NT)
description
The ′BCT25245 is a 25-Ω octal bus transceiver
designed for asynchronous communication
between data buses. It improves both the
performance and density of 3-state memory
address drivers, clock drivers, and bus-oriented
transceivers.
The device allows data transmission from the A
bus to the B bus or from the B bus to the A bus
depending upon the logic level at the
direction-control (DIR) input. The output-enable
(OE
) input can disable the device so that both
buses are effectively isolated.
These transceivers are capable of sinking 188-mA
IOL, which facilitates switching 25-Ω transmission
lines on the incident wave. The distributed V
CC
and GND pins minimize switching noise for more
reliable system operation.
The SN54BCT25245 is characterized for operation over the full military temperature range of
–55°C to 125°C. The SN74BCT25245 is
characterized for operation from 0°C to 70°C.
FUNCTION TABLE
INPUTS
OE
DIR
OPERATION
L L B data to A bus
L H A data to B bus
H X Isolation
1
2
3
4
5
6
7
8
9
10
11
12
24
23
22
21
20
19
18
17
16
15
14
13
A1
GND
A2
A3
GND
A4
A5
GND
A6
A7
GND
A8
DIR
B1
B2
V
CC
B3
B4
B5
B6
V
CC
B7
B8
OE
SN54BCT25245 . . . JT OR W PACKAGE
SN74BCT25245 . . . DW OR NT PACKAGE
(TOP VIEW)
3212827
12 13
5
6
7
8
9
10
11
25
24
23
22
21
20
19
OE
A8
GND
NC
A7
A6
GND
B3
V
CC
B2
NC
B1
DIR
A1
426
14 15 16 17
18
GND
A2
A3
NC
GND
A4
A5
B4B5B6
NCVB7
B8
SN54BCT25245 . . . FK PACKAGE
(TOP VIEW)
CC
NC – No internal connection
UNLESS OTHERWISE NOTED this document contains PRODUCTION
DATA information 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.
SN54BCT25245, SN74BCT25245
25-Ω OCT AL BUS TRANSCEIVERS
WITH 3-STATE OUTPUTS
SCBS053B – MAY 1990 – REVISED APRIL 1994
2–2
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
logic symbol
†
logic diagram (positive logic)
B2
22
B3
20
B4
19
A5
7
A6
9
A7
10
A8
12
A2
3
A3
4
A4
6
OE
A1
1
G3
13
3EN2[AB]
B5
18
B6
17
B7
15
B8
14
B1
23
3EN1[BA]
24
DIR
DIR
OE
A1
B1
24
1
23
13
To Seven Other Channels
1
2
†
This symbol is in accordance with ANSI/IEEE Std 91-1984
and IEC Publication 617-12.
Pin numbers shown are for the DW, JT, NT, and W packages.
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): Control inputs –0.5 V to 7 V. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
I/O ports –0.5 V to 5.5 V. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Voltage range applied to any output in the disabled or power-off state, V
O
–0.5 V to 5.5 V. . . . . . . . . . . . . . . .
Voltage range applied to any output in the high state, V
O
(B port) –0.5 V to V
CC
. . . . . . . . . . . . . . . . . . . . . . . .
Input clamp current, I
IK
–30 mA. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Current into any output in the low state, IO: SN54BCT25245 (A port) 250 mA. . . . . . . . . . . . . . . . . . . . . . . . . .
SN54BCT25245 (B port) 40 mA. . . . . . . . . . . . . . . . . . . . . . . . . . .
SN74BCT25245 (A port) 376 mA. . . . . . . . . . . . . . . . . . . . . . . . . .
SN74BCT25245 (B port) 48 mA. . . . . . . . . . . . . . . . . . . . . . . . . . .
Operating free-air temperature range: SN54BCT25245 –55°C to 125°C. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
SN74BCT25245 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 and output negative-voltage ratings may be exceeded if the input and output clamp-current ratings are observed.
SN54BCT25245, SN74BCT25245
25-Ω OCT AL BUS TRANSCEIVERS
WITH 3-STATE OUTPUTS
SCBS053B – MAY 1990 – REVISED APRIL 1994
2–3
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
recommended operating conditions
SN54BCT25245 SN74BCT25245
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
IL
Low-level input voltage 0.8 0.8 V
I
IK
Input clamp current –18 –18 mA
p
A port –53 –80
IOHHigh-level output current
B port –3 –3
mA
p
A port 125 188
IOLLow-level output current
B port 20 24
mA
T
A
Operating free-air temperature –55 125 0 70 °C
electrical characteristics over recommended operating free-air temperature range (unless
otherwise noted)
SN54BCT25245 SN74BCT25245
PARAMETER
TEST CONDITIONS
MIN TYP†MAX MIN TYP†MAX
UNIT
V
IK
VCC = 4.5 V, II = –18 mA –1.2 –1.2 V
IOH = –53 mA 2
A port
V
CC
= 4.5
V
IOH = – 80 mA 2
V
OH
VCC = 4.75 V , IOH = –3 mA 2.7
V
B port VCC = 4.5 V, IOH = –3 mA 2.4 3.3 2.4 3.3
IOL = 94 mA 0.38 0.55 0.42 0.55
A port VCC = 4.5 V
IOL = 125 mA 0.8
V
OL
IOL = 188 mA 0.7
V
p
IOL = 20 mA 0.3 0.5
B port
V
CC
= 4.5
V
IOL = 24 mA 0.35 0.5
A or B port
0.25 0.25
I
I
Control input
V
CC
= 5.5 V,
V
I
= 5.5
V
0.1 0.1
mA
A or B port
70 70
I
IH
‡
Control input
V
CC
=
5.5 V
,
V
I
=
2.7 V
20 20
µ
A
A or B port
–0.6 –0.6
I
IL
‡
Control input
V
CC
= 5.5 V,
V
I
= 0.5
V
–0.6 –0.6
mA
I
OS
§
B port only
¶
VCC = 5.5 V, VO = 0 –60 –150 –60 –150 mA
A to B
36 46 36 46
I
CCH
B to A
V
CC
=
5.5 V
63 80 63 80
mA
A to B
48 60 48 60
I
CCL
B to A
V
CC
= 5.5
V
95 125 95 125
mA
I
CCZ
VCC = 5.5 V 12 16 12 16 mA
C
i
Control input VCC = 5 V, VI = 2.5 V or 0.5 V 8 8 pF
A port
18 18
p
C
io
B port
V
CC
= 5 V,
V
O
= 2.5 V or 0.5
V
8 8
pF
†
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.
§
Not more than one output should be tested at a time, and the duration of the test should not exceed one second.
¶
Testing for this parameter on the A port is not recommended.
PRODUCT PREVIEW information concerns products in the formative or
design phase of development. Characteristic data and other
specifications are design goals. Texas Instruments reserves the right to
change or discontinue these products without notice.
SN54BCT25245, SN74BCT25245
25-Ω OCT AL BUS TRANSCEIVERS
WITH 3-STATE OUTPUTS
SCBS053B – MAY 1990 – REVISED APRIL 1994
2–4
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
switching characteristics (see Note 2)
PARAMETER
FROM
(INPUT)
TO
(OUTPUT)
VCC = 5 V,
CL = 50 pF,
R1 = 500 Ω,
R2 = 500 Ω,
TA = 25°C
VCC = 4.5 V to 5.5 V,
CL = 50 pF,
R1 = 500 Ω,
R2 = 500 Ω,
TA = MIN to MAX
†
UNIT
′BCT25245 SN54BCT25245 SN74BCT25245
MIN TYP MAX MIN MAX MIN MAX
t
PLH
1.2 3.3 5.1 1.2 5.8 1.2 5.7
t
PHL
A
B
1.9 4.3 6.7 1.9 7.6 1.9 7.2
ns
t
PLH
1.2 3.3 4.8 1.2 5.7 1.2 5.5
t
PHL
B
A
2.1 4 5.6 2.1 6.4 2.1 6.2
ns
t
PZH
3.7 6.3 8.4 3.7 10.1 3.7 9.6
t
PZL
OE
A
4.5 7.4 9.2 4.5 11.1 4.5 10.3
ns
t
PHZ
1.8 3.7 5.5 1.8 6.4 1.8 6.2
t
PLZ
OE
A
3.3 5.1 7.2 3.3 9.6 3.3 8.3
ns
t
PZH
3.4 5.7 7.9 3.4 9.2 3.4 8.9
t
PZL
OE
B
4.3 6.6 8.7 4.3 10.1 4.3 9.7
ns
t
PHZ
2.7 4.5 6.3 2.7 7.2 2.7 6.9
t
PLZ
OE
B
1.7 4.5 6.8 1.7 8.3 1.7 7.5
ns
†
For conditions shown as MIN or MAX, use the appropriate value specified under recommended operating conditions.
NOTE 2: Load circuits and voltage waveforms are shown in Section 1.
PRODUCT PREVIEW information concerns products in the formative or
design phase of development. Characteristic data and other
specifications are design goals. Texas Instruments reserves the right to
change or discontinue these products without notice.
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Copyright 1998, Texas Instruments Incorporated
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