SN55121, SN75121
DUAL LINE DRIVERS
SLLS074C – SEPTEMBER 1973 – REVISED MAY 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
tpd = 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
1B
1A
NC
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
VCC
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 MAY 1998
2POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
FUNCTION TABLE
INPUTS OUTPUT
A B C D E F Y
H H H H X X H
XXXXHH 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
471Y
10
11
12
13 92Y
1A
1B
1C
1D
2A
2B
2C
2D
5
6
1E
1F
14
15
2E
2F
schematic (each driver)
VCC
To Other
Line Driver 4 kΩ4 kΩ
A
B
C
D
E
F
GND
To Other
Line Driver
360 Ω15 Ω
Y
All resistor values shown are nominal.
SN55121, SN75121
DUAL LINE DRIVERS
SLLS074C – SEPTEMBER 1973 – REVISED MAY 1998
3
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
absolute maximum ratings over operating free-air temperature (unless otherwise noted)†
Supply voltage, VCC (see Note 1) 6 V. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Input voltage 6 V. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Output voltage 6 V. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Continuous total power dissipation See Dissipation Rating Table. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Storage temperature range, Tstg –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 af fect 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 F ACTOR
ABOVE TA = 25°CTA = 70°C
POWER RATING TA = 125°C
POWER RATING
D950 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
UNIT
MIN NOM MAX MIN NOM MAX
UNIT
Supply voltage, VCC 4.75 5 5.25 4.75 5 5.25 V
High-level input voltage, VIH 2 2 V
Low-level input voltage, VIL 0.8 0.8 V
High-level output current, IOH –75 –75 mA
Operating free-air temperature, TA–55 125 0 70 °C
SN55121, SN75121
DUAL LINE DRIVERS
SLLS074C – SEPTEMBER 1973 – REVISED MAY 1998
4POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
electrical characteristics over recommended ranges of supply voltage and operating free-air
temperature range (unless otherwise noted)
PARAMETER TEST CONDITIONS MIN MAX UNIT
VIK Input clamp voltage VCC = 5 V, II = –12 mA –1.5 V
V(BR) Breakdown voltage VCC = 5 V, II = 10 mA 5.5 V
VOH High-level output voltage VIH = 2 V, IOH = –75 mA, See Note 2 2.4 V
IOH High-level output current VCC = 5 V,
TA = 25°C, VIH = 4.5 V,
See Note 2 VOH = 2 V, –100 –250 mA
IOL Low-level output current VIL = 0.8 V, VOL = 0.4 V, See Note 2 –800 µA
IO(off) Of f-state output current VCC = 3 V, VO = 3 V 500 µA
IIH High-level output current VI = 4.5 V 40 µA
IIL Low-level output current VI = 0.4 V –0.1 –1.6 mA
IOS Short-circuit output current†VCC = 5 V, TA = 25°C–30 mA
ICCH Supply current, outputs high VCC = 5.25 V, All inputs at 2 V, Outputs open 28 mA
ICCL Supply current, outputs low VCC = 5.25 V, All inputs at 0.8 V, Outputs open 60 mA
†Not more than one output should be shorted at a time.
NOTE 2: The output voltage and current limits are valid for any appropriate combination of high and low inputs specified by the function table
for the desired output.
switching characteristics, VCC = 5 V, TA = 25°C
PARAMETER TEST CONDITIONS MIN TYP MAX UNIT
tPLH Propagation delay time, low-to-high level output
RL=37ΩC
L=15
p
F See Figure 1
11 20
ns
tPHL Propagation delay time, high-to-low level output
R
L =
37
Ω
,
C
L =
15
pF
,
See
Fig
u
re
1
8 20
ns
tPLH Propagation delay time, low-to-high level output
RL=37ΩC
L= 1000
p
F See Figure 1
22 50
ns
tPHL Propagation delay time, high-to-low level output
R
L =
37
Ω
,
C
L =
1000
pF
,
See
Fig
u
re
1
20 50
ns
PARAMETER MEASUREMENT INFORMATION
≤5 ns
0 V
VOH
VOL
3 V
≤5 ns
Input
10% 1.5 V
90%
tPLH
Output
tPHL
VOLTAGE WAVEFORMS
1.5 V 1.5 V
10%
1.5 V
90%
TEST CIRCUIT
Output
3 V VCC
RLCL
(see Note B)
Pulse
Generator
(see Note A)
NOTES: A. The pulse generator has the following characteristics: ZO ≈ 50 Ω, tw = 200 ns, duty cycle ≤ 50%, PRR ≤ 500 kHz.
B. CL includes probe and jig capacitance.
Figure 1. Test Circuit and Voltage Waveforms
SN55121, SN75121
DUAL LINE DRIVERS
SLLS074C – SEPTEMBER 1973 – REVISED MAY 1998
5
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
TYPICAL CHARACTERISTICS
0
IO – Output Current – mA
VO – Output Voltage – V
–300
5
00.5 1 1.5 2 2.5 3 3.5 4 4.5
–50
–100
–150
–200
–250
OUTPUT CURRENT vs OUTPUT VOLTAGE
IO
VCC = 5 V
VIH = 2 V
TA = 25°C
Figure 2
SN55121, SN75121
DUAL LINE DRIVERS
SLLS074C – SEPTEMBER 1973 – REVISED MAY 1998
6POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
APPLICATION INFORMATION
75-Ω Coaxial Cable
1/3 SN55122
1/3 SN55122
1/3 SN55122
1/2 SN55121
1/2 SN55121
1/2 SN55121
75-Ω Coaxial Cable
Cable
75-Ω Coaxial
1/2 SN55121
75 Ω
75 Ω75 Ω
75 Ω
Figure 3. Single-Ended Party-Line Circuits
PACKAGE OPTION ADDENDUM
www.ti.com 7-Jun-2010
Addendum-Page 1
PACKAGING INFORMATION
Orderable Device Status (1) Package Type Package
Drawing Pins Package Qty Eco Plan (2) Lead/
Ball Finish MSL Peak Temp (3) Samples
(Requires Login)
SN55121J OBSOLETE CDIP J 16 TBD Call TI Call TI Samples Not Available
SN75121D OBSOLETE SOIC D 16 TBD Call TI Call TI Samples Not Available
SN75121N ACTIVE PDIP N 16 25 Pb-Free (RoHS) CU NIPDAU N / A for Pkg Type Contact TI Distributor
or Sales Office
SN75121NE4 ACTIVE PDIP N 16 25 Pb-Free (RoHS) CU NIPDAU N / A for Pkg Type Contact TI Distributor
or Sales Office
SN75121NSR ACTIVE SO NS 16 2000 Green (RoHS
& no Sb/Br) CU NIPDAU Level-1-260C-UNLIM Contact TI Distributor
or Sales Office
SN75121NSRE4 ACTIVE SO NS 16 2000 Green (RoHS
& no Sb/Br) CU NIPDAU Level-1-260C-UNLIM Contact TI Distributor
or Sales Office
SN75121NSRG4 ACTIVE SO NS 16 2000 Green (RoHS
& no Sb/Br) CU NIPDAU Level-1-260C-UNLIM Contact TI Distributor
or Sales Office
SNJ55121FK OBSOLETE LCCC FK 20 TBD Call TI Call TI Samples Not Available
SNJ55121J OBSOLETE CDIP J 16 TBD Call TI Call TI Samples Not Available
(1) The marketing status values are defined as follows:
ACTIVE: Product device recommended for new designs.
LIFEBUY: TI has announced that the device will be discontinued, and a lifetime-buy period is in effect.
NRND: Not recommended for new designs. Device is in production to support existing customers, but TI does not recommend using this part in a new design.
PREVIEW: Device has been announced but is not in production. Samples may or may not be available.
OBSOLETE: TI has discontinued the production of the device.
(2) Eco Plan - The planned eco-friendly classification: Pb-Free (RoHS), Pb-Free (RoHS Exempt), or Green (RoHS & no Sb/Br) - please check http://www.ti.com/productcontent for the latest availability
information and additional product content details.
TBD: The Pb-Free/Green conversion plan has not been defined.
Pb-Free (RoHS): TI's terms "Lead-Free" or "Pb-Free" mean semiconductor products that are compatible with the current RoHS requirements for all 6 substances, including the requirement that
lead not exceed 0.1% by weight in homogeneous materials. Where designed to be soldered at high temperatures, TI Pb-Free products are suitable for use in specified lead-free processes.
Pb-Free (RoHS Exempt): This component has a RoHS exemption for either 1) lead-based flip-chip solder bumps used between the die and package, or 2) lead-based die adhesive used between
the die and leadframe. The component is otherwise considered Pb-Free (RoHS compatible) as defined above.
Green (RoHS & no Sb/Br): TI defines "Green" to mean Pb-Free (RoHS compatible), and free of Bromine (Br) and Antimony (Sb) based flame retardants (Br or Sb do not exceed 0.1% by weight
in homogeneous material)
(3) MSL, Peak Temp. -- The Moisture Sensitivity Level rating according to the JEDEC industry standard classifications, and peak solder temperature.
Important Information and Disclaimer:The information provided on this page represents TI's knowledge and belief as of the date that it is provided. TI bases its knowledge and belief on information
provided by third parties, and makes no representation or warranty as to the accuracy of such information. Efforts are underway to better integrate information from third parties. TI has taken and
PACKAGE OPTION ADDENDUM
www.ti.com 7-Jun-2010
Addendum-Page 2
continues to take reasonable steps to provide representative and accurate information but may not have conducted destructive testing or chemical analysis on incoming materials and chemicals.
TI and TI suppliers consider certain information to be proprietary, and thus CAS numbers and other limited information may not be available for release.
In no event shall TI's liability arising out of such information exceed the total purchase price of the TI part(s) at issue in this document sold by TI to Customer on an annual basis.
OTHER QUALIFIED VERSIONS OF SN55121, SN75121 :
•Catalog: SN75121
•Military: SN55121
NOTE: Qualified Version Definitions:
•Catalog - TI's standard catalog product
•Military - QML certified for Military and Defense Applications
TAPE AND REEL INFORMATION
*All dimensions are nominal
Device Package
Type Package
Drawing Pins SPQ Reel
Diameter
(mm)
Reel
Width
W1 (mm)
A0
(mm) B0
(mm) K0
(mm) P1
(mm) W
(mm) Pin1
Quadrant
SN75121NSR SO NS 16 2000 330.0 16.4 8.2 10.5 2.5 12.0 16.0 Q1
PACKAGE MATERIALS INFORMATION
www.ti.com 14-Jul-2012
Pack Materials-Page 1
*All dimensions are nominal
Device Package Type Package Drawing Pins SPQ Length (mm) Width (mm) Height (mm)
SN75121NSR SO NS 16 2000 367.0 367.0 38.0
PACKAGE MATERIALS INFORMATION
www.ti.com 14-Jul-2012
Pack Materials-Page 2
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