Texas Instruments SN55121J, SN75121D, SN75121N, SN75121NS, SNJ55121FK Datasheet
...
SN55121, SN75121
DUAL LINE DRIVERS
SLLS074C – SEPTEMBER 1973 – REVISED MA Y 1998
1
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
D
Designed for Digital Data Transmission
Over 50-Ω to 500-Ω Coaxial Cable, Strip
Line, or Twisted Pair
D
High Speed
t
pd
= 20 ns Maximum at CL = 15 pF
D
TTL Compatible With Single 5-V Supply
D
2.4-V Output at IOH = –75 mA
D
Uncommitted Emitter-Follower Output
Structure for Party-Line Operation
D
Short-Circuit Protection
D
AND-OR Logic Configuration
D
Designed for Use With Triple Line
Receivers SN55122, SN75122
D
Designed to Be Interchangeable With
Signetics N8T13
description
The SN55121 and SN75121 dual line drivers are
designed for digital data transmission over lines
having impedances from 50 to 500 Ω. They are
also compatible with standard TTL logic and
supply-voltage levels.
The low-impedance emitter-follower outputs of
the SN55121 and SN75121 can drive terminated
lines such as coaxial cable or twisted pair. Having
the outputs uncommitted allows wired-OR logic to
be performed in party-line applications. Output
short-circuit protection is provided by an internal
clamping network that turns on when the output
voltage drops below approximately 1.5 V . All of the
inputs are in conventional TTL configuration and
the gating can be used during power-up and
power-down sequences to ensure that no noise is
introduced to the line.
The SN55121 is characterized for operation over
the full military temperature range of –55°C to
125°C. The SN75121 is characterized for
operation from 0°C to 70°C.
Copyright 1998, 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.
3212019
910111213
4
5
6
7
8
18
17
16
15
14
2E
2D
NC
2C
2B
1C
1D
NC
1E
1F
1B1ANC
2Y
2A
2F
1Y
GND
NC
NC–No internal connection
1
2
3
4
5
6
7
8
16
15
14
13
12
11
10
9
1A
1B
1C
1D
1E
1F
1Y
GND
V
CC
2F
2E
2D
2C
2B
2A
2Y
CC
V
THE SN75121 IS NOT
RECOMMENDED FOR NEW DESIGNS
SN55121 ...J PACKAGE
SN75121 ...D OR N PACKAGE
(TOP VIEW)
SN55121 . . . FK PACKAGE
(TOP VIEW)
SN55121, SN75121
DUAL LINE DRIVERS
SLLS074C – SEPTEMBER 1973 – REVISED MA Y 1998
2
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
FUNCTION TABLE
INPUTS
OUTPUT
A B C D E F
Y
H H H H X X H
X XXXHH H
All other input combinations L
H = high level, L = low level, X = irrelevant
logic symbol
†
&1
2Y
1Y
9
7
&
2F
2E
2D
2C
2B
2A
1F
1E
1D
1C
1B
1A
15
14
13
12
11
10
6
5
4
3
2
1
≥
†
This symbol is in accordance with ANSI/IEEE Std 91-1984 and
IEC Publication 617-12.
Pin numbers shown are for the D, J, and N packages.
logic diagram (positive logic)
1
2
3
4
7
1Y
10
11
12
13
9
2Y
1A
1B
1C
1D
2A
2B
2C
2D
5
6
1E
1F
14
15
2E
2F
schematic (each driver)
V
CC
To Other
Line Driver
4 kΩ 4 kΩ
A
B
C
D
E
F
GND
To Other
Line Driver
360 Ω 15 Ω
Y
All resistor values shown are nominal.
SN55121, SN75121
DUAL LINE DRIVERS
SLLS074C – SEPTEMBER 1973 – REVISED MA Y 1998
3
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
absolute maximum ratings over operating free-air temperature (unless otherwise noted)
†
Supply voltage, V
CC
(see Note 1) 6 V. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Input voltage 6 V. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Output voltage 6 V. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Continuous total power dissipation See Dissipation Rating Table. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Storage temperature range, T
stg
–65°C to 150°C. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Case temperature for 60 seconds: FK package 260°C. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Lead temperature 1,6 mm (1/16 inch) from case for 60 seconds: J package 300°C. . . . . . . . . . . . . . . . . . . . .
Lead temperature 1,6 mm (1/16 inch) from case for 10 seconds: D or N package 260°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: All voltage values are with respect to both ground terminals connected together.
DISSIPATION RATING TABLE
PACKAGE
TA ≤ 25°C
POWER RATING
DERATING FACTOR
ABOVE TA = 25°C
TA = 70°C
POWER RATING
TA = 125°C
POWER RATING
D 950 mW 7.6 mW/°C 608 mW —
FK
‡
1375 mW 11.0 mW/°C 880 mW 275 mW
J
‡
1375 mW 11.0 mW/°C 880 mW 275 mW
N 1150 mW 9.2 mW/°C 736 mW —
‡
In the FK and J packages, SN55121 chips are either silver glass or alloy mounted.
recommended operating conditions
SN55121 SN75121
MIN NOM MAX MIN NOM MAX
UNIT
Supply voltage, V
CC
4.75 5 5.25 4.75 5 5.25 V
High-level input voltage, V
IH
2 2 V
Low-level input voltage, V
IL
0.8 0.8 V
High-level output current, I
OH
–75 –75 mA
Operating free-air temperature, T
A
–55 125 0 70 °C
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