Page 1
SN55LBC174
QUADRUPLE LOW-POWER DIFFERENTIAL LINE DRIVER
SGLS082 – MARCH 1995
1
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
D
Meets EIA Standard RS-485
D
Designed for High-Speed Multipoint
Transmission on Long Bus Lines in Noisy
Environments
D
Supports Data Rates up to and Exceeding
Ten Million Transfers Per Second
D
Common-Mode Output Voltage Range of
–7 V to 12 V
D
Positive- and Negative-Current Limiting
D
Low Power Consumption...1.5 mA Max
(Output Disabled)
description
The SN55LBC174 is composed of monolithic
quadruple differential line drivers with 3-state
outputs. This device is designed to meet the
requirements of the Electronics Industry
Association (EIA) Standard RS-485 and is
optimized for balanced multipoint bus
transmission at data rates up to and exceeding 10
million bits per second. Each driver features wide
positive and negative common-mode output
voltage ranges, current limiting, and
thermal-shutdown protection making it suitable
for party-line applications in noisy environments.
This device is designed using LinBiCMOS,
facilitating ultra-low power consumption and
inherent robustness.
The SN55LBC174 provides positive and negative-current limiting and thermal shutdown for protection from line
fault conditions on the transmission bus line. This device offers optimum performance when used with the
SN55LBC173 quadruple line receiver . The SN55LBC174 is available in the 16-pin CDIP package (J), the 16-pin
CPAK (W), or the 20-pin LCCC package (FK).
The SN55LBC174 is characterized for operation over the military temperature range of –55°C to 125°C.
FUNCTION TABLE
(each driver)
OUTPUTS
INPUT
ENABLE
Y Z
H H H L
L H L H
X L Z Z
H = high level, L = low level, X = irrelevant,
Z = high impedance (off)
Copyright 1995, 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.
1
2
3
4
5
6
7
8
16
15
14
13
12
11
10
9
1A
1Y
1Z
1,2EN
2Z
2Y
2A
GND
V
CC
4A
4Y
4Z
3,4EN
3Z
3Y
3A
J OR W PACKAGE
(TOP VIEW)
NC – No internal connection
FK PACKAGE
(TOP VIEW)
1920132
17
18
16
15
14
1312119 10
5
4
6
7
8
4Y
4Z
NC
3,4EN
3Z
3Z
1,2EN
NC
2Z
2Y
1Y1ANC
4A
GND
NC
3A
3Y
2A
V
CC
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.
LinBiCMOS is a trademark of Texas Instruments Incorporated.
Page 2
SN55LBC174
QUADRUPLE LOW-POWER DIFFERENTIAL LINE DRIVER
SGLS082 – MARCH 1995
2
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
logic symbol
†
EN
EN
4A
3A
3,4EN
2A
1A
1,2EN
15
9
12
7
1
4
4Z
4Y
3Z
3Y
2Z
2Y
1Z
1Y
13
14
11
10
5
6
3
2
†
This symbol is in accordance with ANSI/IEEE Std 91-1984
and IEC Publication 617-12.
Pin numbers shown are for the J or W package.
logic diagram (positive logic)
1A
1Y
1Z
2A
2Y
2Z
1,2EN
3A
3Y
3Z
4A
4Y
4Z
3,4EN
1
4
7
9
12
15
13
14
11
10
5
6
3
2
schematic of inputs and outputs
Input
50 µA
V
CC
Driver
Output
V
CC
200 Ω
ALL INPUTS Y OR Z OUTPUT
Page 3
SN55LBC174
QUADRUPLE LOW-POWER DIFFERENTIAL LINE DRIVER
SGLS082 – MARCH 1995
3
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
absolute maximum ratings over operating free-air temperature (unless otherwise noted)
†
Supply voltage range, V
CC
(see Note 1) –0.3 V to 7 V. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Output voltage range, V
O
–10 V to 15 V. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Input voltage range, V
I
–0.3 V to 7 V. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Continuous power dissipation internally limited
‡
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Operating free-air temperature range, T
A
–55°C to 125°C. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Storage temperature range, T
stg
–65°C to 150°C. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Lead temperature 1,6 mm (1/16 inch) from case for 10 seconds –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.
‡
The maximum operating junction temperature is internally limited. Use the dissipation rating table to operate below this temperature.
NOTE 1: All voltage values are with respect to GND.
DISSIPATION RATING TABLE
PACKAGE
TA ≤ 25°C
POWER RATING
DERATING FACTOR
ABOVE TA = 25°C
TA = 125°C
POWER RATING
FK 1375 mW 11.0 mW/°C 275 mW
J 1375 mW 11.0 mW/°C 275 mW
W 1000 mW 8.0 mW/°C 200 mW
recommended operating conditions
MIN NOM MAX UNIT
Supply voltage, V
CC
4.75 5 5.25 V
High-level input voltage, V
IH
2 V
Low-level input voltage, V
IL
0.8 V
p
12
Voltage at any bus terminal (separately or common mode), V
O
Y or Z–7V
High-level output current, I
OH
Y or Z –60 mA
Low-level output current, I
OL
Y or Z 60 mA
Operating free-air temperature, T
A
–55 125 °C
Page 4
SN55LBC174
QUADRUPLE LOW-POWER DIFFERENTIAL LINE DRIVER
SGLS082 – MARCH 1995
4
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
electrical characteristics over recommended ranges of supply voltage and operating free-air
temperature (unless otherwise noted)
PARAMETER TEST CONDITIONS MIN TYP†MAX UNIT
V
IK
Input clamp voltage II = –18 mA –1.5 V
RL = 54 Ω, See Figure 1 1.1 1.8 5
|VOD|
Diff
erential output voltage
‡
RL = 60 Ω, See Figure 2 1.1 1.7 5
V
∆|VOD|
Change in magnitude of differential output voltage
§
±0.2 V
3
V
OC
C
ommon-mode output voltage
R
L
= 54 Ω,
See Figure 1
–1
V
∆|VOC|
Change in magnitude of common-mode output voltage
§
±0.2 V
I
O
Output current with power off VCC = 0, VO = – 7 V to 12 V ±100 µA
I
OZ
High-impedance-state output current VO = – 7 V to 12 V ±100 µA
I
IH
High-level input current VI = 2.4 V –100 µA
I
IL
Low-level input current VI = 0.4 V –100 µA
I
OS
Short-circuit output current VO = –7 V to 12 V ±250 mA
pp
Outputs enabled 7
ICCSupply current (all drivers)
No load
Outputs disabled 1.5
mA
†
All typical values are at VCC = 5 V and TA = 25°C.
‡
The minimum VOD specification does not fully comply with EIA Standard RS-485 at operating temperatures below 0°C. The lower output signal
should be used to determine the maximum signal transmission distance.
§
∆|VOD| and ∆|VOC| are the changes in magnitude of VOD and VOC, respectively, that occur when the input is changed from a high level to a low
level.
switching characteristics, VCC = 5 V
PARAMETER TEST CONDITIONS T
A
MIN TYP MAX UNIT
p
25°C 2 11 20
t
d(OD)
Differential output delay time
R
L
=
54 Ω
,
See Figure 3
–55°C to 125°C 2 40
ns
p
25°C 4 15 25
t
t(OD)
Differential output transition time
R
L
= 54 Ω,
See Figure 3
–55°C to 125°C 4 40
ns
p
25°C 30
t
PZH
Output enable time to high level
R
L
=
110 Ω
,
See Figure 4
–55°C to 125°C 40
ns
p
25°C 30
t
PZL
Output enable time to low level
R
L
=
110 Ω
,
See Figure 5
–55°C to 125°C 40
ns
p
25°C 50
t
PHZ
Output disable time from high level
R
L
=
110 Ω
,
See Figure 4
–55°C to 125°C 90
ns
p
25°C 30
t
PLZ
Out ut disable time from low level
R
L
=
110 Ω
,
See Figure 5
–55°C to 125°C 45
ns
Page 5
SN55LBC174
QUADRUPLE LOW-POWER DIFFERENTIAL LINE DRIVER
SGLS082 – MARCH 1995
5
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
PARAMETER MEASUREMENT INFORMATION
V
OC
2
R
L
2
R
L
V
OD2
Figure 1. Differential and Common-Mode Output Voltages
R2 = 375 Ω
V
OD
RL = 60 Ω
V
test
V
test
0 V or 3 V
A
R1 = 375 Ω
Y
Z
–7 V < V
test
< 12 V
EN at 5 V
Figure 2. Driver VOD Test Circuit
VOLTAGE WAVEFORMS
50%
t
t(OD)
t
d(OD)
10%
t
t(OD)
≈ 2.5 V
≈ – 2.5 V
90%
50%
Output
t
d(OD)
0 V
3 V
Input
Output
1.5 V 1.5 V
TEST CIRCUIT
CL = 50 pF
(see Note B)
RL = 54 Ω
50 Ω
Generator
(see Note A)
3 V
Input
NOTES: A. The input pulse is supplied by a generator having the following characteristics: PRR ≤ 1 MHz, duty cycle ≤ 50%, tr ≤ 5 ns,
tf ≤ 5 ns, ZO = 50 Ω.
B. CL includes probe and stray capacitance.
Figure 3. Driver Differential-Output Test Circuit Delay and Transition-Time Waveforms
Page 6
SN55LBC174
QUADRUPLE LOW-POWER DIFFERENTIAL LINE DRIVER
SGLS082 – MARCH 1995
6
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
PARAMETER MEASUREMENT INFORMATION
RL = 110 Ω
VOLTAGE WAVEFORMSTEST CIRCUIT
Output
Input
t
PZH
1.5 V
2.3 V
0.5 V
t
PHZ
1.5 V
V
OH
V
off
≈ 0 V
0 V
3 V
Output
3 V or 0 V
S1
CL = 50 pF
(see Note B)
Generator
(see Note A)
50 Ω
Input
NOTES: A. The input pulse is supplied by a generator having the following characteristics: PRR ≤ 1 MHz, duty cycle ≤ 50%, tr ≤ 5 ns,
tf ≤ 5 ns, ZO = 50 Ω.
B. CL includes probe and stray capacitance.
Figure 4. t
PZH
and t
PHZ
Test Circuit and Waveforms
VOLTAGE WAVEFORMSTEST CIRCUIT
Output
RL = 110 Ω
5 V
5 V
V
OL
0.5 V
t
PZL
3 V
t
PLZ
1.5 V
2.3 V
1.5 V
Output
Input
0 V
0 V or 3 V
S1
CL = 50 pF
(see Note B)
Generator
(see Note A)
50 Ω
Input
NOTES: A. The input pulse is supplied by a generator having the following characteristics: PRR ≤ 1 MHz, duty cycle ≤ 50%, tr ≤ 5 ns,
tf ≤ 5 ns, ZO = 50 Ω.
B. CL includes probe and stray capacitance.
Figure 5. t
PZL
and t
PLZ
Test Circuit and Waveforms
Page 7
SN55LBC174
QUADRUPLE LOW-POWER DIFFERENTIAL LINE DRIVER
SGLS082 – MARCH 1995
7
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
TYPICAL CHARACTERISTICS
Figure 6
IO – Output Current – A
VO – Output Voltage – V
OUTPUT CURRENT
vs
OUTPUT VOLTAGE
Output Disabled
TA = 25°C
40
30
20
10
0
–10
–20
–30
–40
20151050–5–10–15–20
–50
25
50
–25
I
O
VCC = 5 V
VCC = 0
µ
Figure 7
IOL – Low-Level Output Current – mA
LOW-LEVEL OUTPUT VOLTAGE
vs
LOW-LEVEL OUTPUT CURRENT
– Low-Level Output Voltage – V
OL
V
3.5
3
2.5
2
1.5
1
0.5
8060
4020
0
4
0
100
VCC = 5 V
TA = 25°C
4.5
5
120
–20
Figure 8
3
2.5
2
1.5
1
0.5
4020
0–20–40
0
60
TA – Free-Air Temperature – °C
– Differential Output Voltage – V
–60
DIFFERENTIAL OUTPUT VOLTAGE
vs
FREE-AIR TEMPERATURE
V
OD
80 100
RL = 54 Ω
VCC = 5 V
Figure 9
IOH – High-Level Output Current – mA
– High-Level Output Voltage – V
4.5
4
3.5
3
2.5
2
1.5
5
HIGH-LEVEL OUTPUT VOLTAGE
vs
HIGH-LEVEL OUTPUT CURRENT
–40–20 –600
V
OH
–80
–100
VCC = 5 V
TA = 25°C
–120
20
Page 8
SN55LBC174
QUADRUPLE LOW-POWER DIFFERENTIAL LINE DRIVER
SGLS082 – MARCH 1995
8
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
TYPICAL CHARACTERISTICS
Figure 10
IO – Output Current – mA
DIFFERENTIAL OUTPUT VOLTAGE
vs
OUTPUT CURRENT
3
2.5
2
1.5
1
0.5
90807060
5040302010
0
– Differential Output Voltage – V
0
OD
V
100
VCC = 5 V
TA = 25°C
Figure 11
TA – Free-Air Temperature – °C
PROPAGATION DELAY TIME,
DIFFERENTIAL OUTPUT
vs
FREE-AIR TEMPERATURE
11
10
9
8
7
6
5
1008060
40200–20–40
4
12
Propagation Delay Time, Differential Output – ns
–60
13
14
RL = 54 Ω
CL = 50 pF
VCC = 5 V
Page 9
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