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SN65LVDS179, SN65LVDS180, SN65LVDS050, SN65LVDS051
SLLS301R – APRIL 1998 – REVISED JANUARY 2016
SN65LVDSxxx High-Speed Differential Line Drivers and Receivers
1 Features
3 Description
•
The SN65LVDS179, SN65LVDS180, SN65LVDS050,
and SN65LVDS051 devices are differential line
drivers and receivers that use low-voltage differential
signaling (LVDS) to achieve signaling rates as high
as 400 Mbps (see Table 1). The TIA/EIA-644
standard-compliant electrical interface provides a
minimum differential output voltage magnitude of 247
mV into a 100-Ω load and receipt of 100-mV signals
with up to 1 V of ground potential difference between
a transmitter and receiver.
1
•
•
•
•
•
•
•
•
•
Meets or Exceeds the Requirements of ANSI
TIA/EIA-644-1995 Standard
Full-Duplex Signaling Rates up to 150 Mbps (See
Table 1)
Bus-Pin ESD Exceeds 12 kV
Operates From a Single 3.3-V Supply
Low-Voltage Differential Signaling With Typical
Output Voltages of 350 mV and a 100-Ω Load
Propagation Delay Times
– Driver: 1.7 ns Typical
– Receiver: 3.7 ns Typical
Power Dissipation at 200 MHz
– Driver: 25 mW Typical
– Receiver: 60 mW Typical
LVTTL Input Levels Are 5-V Tolerant
Receiver Maintains High Input Impedance With
VCC < 1.5 V
Receiver Has Open-Circuit Fail Safe
Device Information(1)
PART NUMBER
SN65LVDS179
SN65LVDS180
SN65LVDS050
SN65LVDS051
BODY SIZE (NOM)
SOIC (8)
4.90 mm × 3.91 mm
VSSOP (8)
3.00 mm × 3.00 mm
SOIC (14)
8.65 mm × 3.91 mm
TSSOP (14)
5.00 mm × 4.40 mm
SOIC (16)
9.90 mm × 3.91 mm
TSSOP (16)
5.00 mm × 4.40 mm
SOIC (16)
9.90 mm × 3.91 mm
TSSOP (16)
5.00 mm × 4.40 mm
(1) For all available packages, see the orderable addendum at
the end of the data sheet.
2 Applications
•
•
•
PACKAGE
Wireless Infrastructure
Telecom Infrastructure
Printer
Equivalent Input and Output Schematic Diagrams
VCC
VCC
VCC
300 kΩ
50 Ω
5Ω
10 kΩ
D or
RE
Input
Y or Z
Output
50 Ω
DE
Input
7V
300 kΩ
7V
7V
VCC
VCC
300 kΩ
300 kΩ
5Ω
A Input
R Output
B Input
7V
7V
7V
1
An IMPORTANT NOTICE at the end of this data sheet addresses availability, warranty, changes, use in safety-critical applications,
intellectual property matters and other important disclaimers. PRODUCTION DATA.
SN65LVDS179, SN65LVDS180, SN65LVDS050, SN65LVDS051
SLLS301R – APRIL 1998 – REVISED JANUARY 2016
www.ti.com
Table of Contents
1
2
3
4
5
6
7
8
Features ..................................................................
Applications ...........................................................
Description .............................................................
Revision History.....................................................
Description (Continued) ........................................
Device Options.......................................................
Pin Configuration and Functions .........................
Specifications.........................................................
8.1
8.2
8.3
8.4
8.5
8.6
8.7
8.8
8.9
8.10
9
1
1
1
2
3
3
4
6
Absolute Maximum Ratings ..................................... 6
ESD Ratings.............................................................. 6
Recommended Operating Conditions....................... 7
Thermal Information .................................................. 7
Device Electrical Characteristics .............................. 7
Driver Electrical Characteristics ............................... 8
Receiver Electrical Characteristics .......................... 8
Driver Switching Characteristics ............................... 9
Receiver Switching Characteristics .......................... 9
Typical Characteristics .......................................... 10
Parameter Measurement Information ................ 12
9.1 Driver....................................................................... 12
9.2 Receiver .................................................................. 14
10 Detailed Description ........................................... 17
10.1
10.2
10.3
10.4
Overview ...............................................................
Functional Block Diagram .....................................
Feature Description...............................................
Device Functional Modes......................................
17
17
17
20
11 Application and Implementation........................ 22
11.1 Application Information.......................................... 22
11.2 Typical Application ................................................ 22
12 Power Supply Recommendations ..................... 28
13 Layout................................................................... 28
13.1 Layout Guidelines ................................................. 28
13.2 Layout Example .................................................... 30
14 Device and Documentation Support ................. 32
14.1
14.2
14.3
14.4
14.5
14.6
Device Support......................................................
Documentation Support ........................................
Related Links ........................................................
Trademarks ...........................................................
Electrostatic Discharge Caution ............................
Glossary ................................................................
32
32
32
32
32
32
15 Mechanical, Packaging, and Orderable
Information ........................................................... 33
4 Revision History
Changes from Revision Q (December 2014) to Revision R
Page
•
Changed pin A in the Pin Functions: SN65LVDS179 From: "non-inverting output" To: "non-inverting input" ....................... 5
•
Changed pin B in the Pin Functions: SN65LVDS179 From: "inverting output" To: "inverting input" .................................... 5
Changes from Revision P (April 2009) to Revision Q
•
2
Page
Added Pin Configuration and Functions section, ESD Ratings table, Feature Description section, Device Functional
Modes, Application and Implementation section, Power Supply Recommendations section, Layout section, Device
and Documentation Support section, and Mechanical, Packaging, and Orderable Information section .............................. 1
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SLLS301R – APRIL 1998 – REVISED JANUARY 2016
5 Description (Continued)
These devices offer various driver, receiver, and enabling combinations in industry-standard footprints. Because
these devices are intended for use in simplex or distributed simplex bus structures, the driver enable function
does not put the differential outputs into a high-impedance state but rather disconnects the input and reduces the
quiescent power used by the device. For these functions with a high-impedance driver output, see the
SN65LVDM series of devices. All devices are characterized for operation from –40°C to 85°C.
6 Device Options
PACKAGE
SMALL OUTLINE (D)
SMALL OUTLINE (DGK)
SMALL OUTLINE (PW)
SN65LVDS050D
—
SN65LVDS050PW
SN65LVDS051D
—
SN65LVDS051PW
SN65LVDS179D
SN65LVDS179DGK
—
SN65LVDS180D
—
SN65LVDS180PW
Table 1. Maximum Recommended Operating Speeds
PART NUMBER
ALL BUFFERS ACTIVE
RX BUFFER ONLY
TX BUFFER ONLY
SN65LVDS179
150 Mbps
150 Mbps
400 Mbps
SN65LVDS180
150 Mbps
150 Mbps
400 Mbps
SN65LVDS050
100 Mbps
100 Mbps
400 Mbps
SN65LVDS051
100 Mbps
100 Mbps
400 Mbps
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3
SN65LVDS179, SN65LVDS180, SN65LVDS050, SN65LVDS051
SLLS301R – APRIL 1998 – REVISED JANUARY 2016
www.ti.com
7 Pin Configuration and Functions
SN65LVDS179D (Marked as DL179 or LVD179)
SN65LVDS179DGK (Marked as S79)
(TOP VIEW)
3
VCC
R
D
GND
1
8
2
7
3
6
4
5
A
B
Z
Y
D
5
6
8
2
R
7
Y
Z
A
B
SN65LVDS180D (Marked as LVDS180)
SN65LVDS180PW (Marked as LVDS180)
(TOP VIEW)
NC
R
RE
DE
D
GND
GND
1
14
2
13
3
12
4
11
5
10
6
9
7
8
VCC
VCC
A
B
Z
Y
NC
5
4
DE
1
16
2
15
3
14
4
13
5
12
6
11
7
10
8
9
VCC
1D
1Y
1Z
DE
2Z
2Y
2D
RE
12
2
R
4
13
5
12
6
11
7
10
8
9
1Z
2DE
2Z
2Y
2D
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14
13
10
9
2D
3
1R
11
2
1
4
RE
6
5
2R
9
7
14
13
2
1
10
11
2D
12
6
2DE
5
2R
4
11
12
DE
SN65LVDS051D (Marked as LVDS051)
SN65LVDS051PW (Marked as LVDS051)
(TOP VIEW)
15
1D
1B 1
16 VCC
4
1DE
1A 2
15 1D
3
1R 3
14 1Y
1R
1DE
2R
2A
2B
GND
Y
Z
3
SN65LVDS050D (Marked as LVDS050)
SN65LVDS050PW (Marked as LVDS050)
15
(TOP VIEW)
1D
1B
1A
1R
RE
2R
2A
2B
GND
9
10
D
7
A
B
1Y
1Z
2Y
2Z
1A
1B
2A
2B
1Y
1Z
1A
1B
2Y
2Z
2A
2B
Copyright © 1998–2016, Texas Instruments Incorporated
Product Folder Links: SN65LVDS179 SN65LVDS180 SN65LVDS050 SN65LVDS051
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SLLS301R – APRIL 1998 – REVISED JANUARY 2016
Pin Functions: SN65LVDS179
PIN
NAME
NUMBER
I/O
DESCRIPTION
VCC
1
–
Supply voltage
GND
4
–
Ground
D
3
I
LVTTL input signal
Y
5
O
Differential (LVDS) non-inverting output
Z
6
O
Differential (LVDS) inverting output
R
2
O
LVTTL output signal
A
8
I
Differential (LVDS) non-inverting input
B
7
I
Differential (LVDS) inverting input
Pin Functions: SN65LVDS180
PIN
NAME
NUMBER
I/O
DESCRIPTION
VCC
13, 14
–
Supply voltage
GND
6, 7
–
Ground
D
5
I
LVTTL input signal
Y
9
O
Differential (LVDS) non-inverting output
Z
10
O
Differential (LVDS) inverting output
R
2
O
LVTTL output signal
A
12
I
Differential (LVDS) non-inverting input
B
11
I
Differential (LVDS) inverting input
DE
4
I
Driver enable
RE/
3
I
Receiver enable
NC
1, 8
–
No connection
Pin Functions: SN65LVDS050
PIN
NAME
NUMBER
I/O
DESCRIPTION
VCC
16
–
Supply voltage
GND
8
–
Ground
1D
15
I
LVTTL input signal
1Y
14
O
Differential (LVDS) non-inverting output
1Z
13
O
Differential (LVDS) inverting output
2D
9
I
LVTTL input signal
2Y
10
O
Differential (LVDS) non-inverting output
2Z
11
O
Differential (LVDS) inverting output
1R
3
O
LVTTL output signal
1A
2
I
Differential (LVDS) non-inverting input
1B
1
I
Differential (LVDS) inverting input
2R
5
O
LVTTL output signal
2A
6
I
Differential (LVDS) non-inverting input
2B
7
I
Differential (LVDS) inverting input
DE
12
I
Driver enable
RE/
4
I
Receiver enable
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Pin Functions: SN65LVDS051
PIN
NAME
NUMBER
I/O
DESCRIPTION
VCC
16
–
Supply voltage
GND
8
–
Ground
1D
15
I
LVTTL input signal
1Y
14
O
Differential (LVDS) non-inverting output
1Z
13
O
Differential (LVDS) inverting output
2D
9
I
LVTTL input signal
2Y
10
O
Differential (LVDS) non-inverting output
2Z
11
O
Differential (LVDS) inverting output
1R
3
O
LVTTL output signal
1A
2
I
Differential (LVDS) non-inverting input
1B
1
I
Differential (LVDS) inverting input
2R
5
O
LVTTL output signal
2A
6
I
Differential (LVDS) non-inverting input
2B
7
I
Differential (LVDS) inverting input
1DE
4
I
Driver 1 enable
2DE
12
I
Driver 2 enable
8 Specifications
8.1 Absolute Maximum Ratings (1)
over operating free-air temperature range (unless otherwise noted)
VCC (2)
Voltage range:
|VOD|
MIN
MAX
UNIT
–0.5
4
V
D, R, DE, RE
–0.5
6
V
Y, Z, A, and B
–0.5
4
V
1
V
Supply voltage range
Differential output voltage
Continuous power dissipation
Tstg
(1)
(2)
See Thermal
Information
Storage temperature
–65
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.
All voltage values, except differential I/O bus voltages are with respect to network ground terminal.
8.2 ESD Ratings
Y, Z, A, B , and GND (see
V(ESD)
Electrostatic discharge
All
(1)
)
VALUE
UNIT
±12000
V
Class 3, B
±600
V
Class 3, A
±7000
V
Class 3, B
±500
V
250
°C
Class 3, A
Lead temperature 1.6 mm (1/16 inch) from case for 10 seconds
(1)
6
Tested in accordance with MIL-STD-883C Method 3015.7.
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SLLS301R – APRIL 1998 – REVISED JANUARY 2016
8.3 Recommended Operating Conditions
MIN
NOM
MAX
VCC
Supply voltage
3
3.3
3.6
VIH
High-level input voltage
2
VIL
Low-level input voltage
|VID|
Magnitude of differential input voltage
|VOD(dis)|
Magnitude of differential output voltage with disabled driver
VOY or VOZ
Driver output voltage
VIC
Common-mode input voltage (see Figure 14)
TA
Operating free-air temperature
UNIT
V
V
0.8
0.05
0
V
0.6
V
520
mV
2.4
V
VCC – 0.8
V
85
°C
–40
8.4 Thermal Information
THERMAL METRIC (1)
SN65LVDS179
SN65LVDS180
D
DGK
D
8 PINS
(1)
(2)
SN65LVDS050,
SN65LVDS051
PW
D
14 PINS
UNIT
PW
16 PINS
Power Rating: TA≤ 25°C
635
424
987
736
1110
839
Derating Factor Above TA = 25°C (2)
5.1
3.4
7.9
5.9
8.9
6.7
Power Rating: TA = 85°C
330
220
513
383
577
437
mW
mW/°C
For more information about traditional and new thermal metrics, see the IC Package Thermal Metrics application report, SPRA953.
This is the inverse of the junction-to-ambient thermal resistance when board-mounted and with no airflow.
8.5 Device Electrical Characteristics
over recommended operating conditions (unless otherwise noted)
TYP (1)
MAX
No receiver load, driver RL = 100 Ω
9
12
Driver and receiver enabled, no receiver load,
driver RL = 100 Ω
9
12
PARAMETER
TEST CONDITIONS
SN65LVDS179
SN65LVDS180
ICC
Supply
current
SN65LVDS050
Driver enabled, receiver disabled, RL = 100 Ω
5
7
Driver disabled, receiver enabled, no load
1.5
2
Disabled
0.5
1
Drivers and receivers enabled, no receiver loads,
driver RL = 100 Ω
12
20
Drivers enabled, receivers disabled, RL = 100 Ω
10
16
3
6
Disabled
0.5
1
Drivers enabled, no receiver loads, driver RL =
100 Ω
12
20
3
6
Drivers disabled, receivers enabled, no loads
SN65LVDS051
Drivers disabled, no loads
(1)
MIN
UNIT
mA
mA
mA
mA
All typical values are at 25°C and with a 3.3-V supply.
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8.6 Driver Electrical Characteristics
over recommended operating conditions (unless otherwise noted)
PARAMETER
TEST CONDITIONS
|VOD|
Differential output voltage magnitude
Δ|VOD|
Change in differential output voltage magnitude
between logic states
VOC(SS)
Steady-state common-mode output voltage
ΔVOC(SS)
Change in steady-state common-mode output
voltage between logic states
VOC(PP)
Peak-to-peak common-mode output voltage
IIH
High-level input current
IIL
Low-level input current
IOS
Short-circuit output current
DE
D
DE
D
RL = 100 Ω, See
Figure 11 and
Figure 12
MIN
TYP
MAX
247
340
454
–50
1.125
See Figure 12
50
1.2
–50
1.375
UNIT
mV
V
50
mV
50
150
mV
–0.5
–20
2
20
–0.5
–10
2
10
VOY or VOZ = 0 V
3
10
VOD = 0 V
3
10
VIH = 5 V
VIL = 0.8 V
μA
μA
mA
DE = 0 V
VOY = VOZ = 0 V
IO(OFF)
Off-state output current
CIN
Input capacitance
DE = VCC
VOY = VOZ = 0 V
VCC < 1.5 V
–1
1
3
µA
pF
8.7 Receiver Electrical Characteristics
over recommended operating conditions (unless otherwise noted)
PARAMETER
VIT+
TEST CONDITIONS
MIN
TYP (1)
Positive-going differential input voltage threshold
VIT–
See Figure 14 and
Negative-going differential input voltage threshold Table 2
VOH
High-level output voltage
VOL
Low-level output voltage
100
–100
IOH = –8 mA
2.4
IOH = –4 mA
2.8
UNIT
mV
V
IOL = 8 mA
VI = 0 V
MAX
0.4
–2
–11
–1.2
–3
–20
V
μA
II
Input current (A or B input)
II(OFF)
Power-off input current (A or B input)
VCC = 0 V
±20
μA
IIH
High-level input current (enables)
VIH = 5 V
±10
μA
IIL
Low-level input current (enables)
VIL = 0.8 V
±10
μA
IOZ
High-impedance output current
VO = 0 or 5 V
±10
μA
CI
Input capacitance
(1)
8
VI = 2.4 V
5
pF
All typical values are at 25°C and with a 3.3-V supply.
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8.8 Driver Switching Characteristics
over recommended operating conditions (unless otherwise noted)
PARAMETER
TEST CONDITIONS
MIN
TYP (1)
MAX
UNIT
tPLH
Propagation delay time, low-to-high-level output
1.7
2.7
ns
tPHL
Propagation delay time, high-to-low-level output
1.7
2.7
ns
tr
Differential output signal rise time
0.8
1
ns
tf
Differential output signal fall time
0.8
1
ns
RL = 100 Ω
CL = 10 pF
See Figure 11
(2)
tsk(p)
Pulse skew (|tpHL – tpLH|)
tsk(o)
Channel-to-channel output skew (3)
150
ten
Enable time
4.3
10
ns
tdis
Disable time
3.1
10
ns
(1)
(2)
(3)
300
See Figure 13
ps
ps
All typical values are at 25°C and with a 3.3-V supply.
tsk(p) is the magnitude of the time difference between the high-to-low and low-to-high propagation delay times at an output.
tsk(o) is the magnitude of the time difference between the outputs of a single device with all of their inputs connected together.
8.9 Receiver Switching Characteristics
over recommended operating conditions (unless otherwise noted)
PARAMETER
TEST CONDITIONS
MIN
TYP (1)
MAX
UNIT
tPLH
Propagation delay time, low-to-high-level output
3.7
4.5
ns
tPHL
Propagation delay time, high-to-low-level output
3.7
4.5
ns
tsk(p)
Pulse skew (|tpHL – tpLH|) (2)
tr
Output signal rise time
0.7
1.5
ns
tf
Output signal fall time
0.9
1.5
ns
tPZH
Propagation delay time, high-impedance-to-highlevel output
2.5
ns
tPZL
Propagation delay time, high-impedance-to-lowlevel output
2.5
ns
7
ns
4
ns
tPHZ
Propagation delay time, high-level-to-highimpedance output
tPLZ
Propagation delay time, low-level-to-highimpedance output
(1)
(2)
CL = 10 pF,
See Figure 15
0.3
ns
See Figure 16
All typical values are at 25°C and with a 3.3-V supply.
tsk(p) is the magnitude of the time difference between the high-to-low and low-to-high propagation delay times at an output.
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8.10 Typical Characteristics
4
VCC = 3.3 V
TA = 25°C
DE = 0 V
30
20
Other output at 1.2 V
10
VOZ = VOY
0
−10
Other output at 2.4 V
3
2
1
−20
−30
0
0
0.5
1
1.5
2
VO − Output Voltage − V
2.5
0
3
6
5
VCC = 3.3 V
TA = 25°C
VCC = 3.3 V
TA = 25°C
VOL − Low-Level Output Votlage − V
3
2.5
2
1.5
1
0.5
4
3
2
1
0
0
−4
−3
−2
−1
0
0
IOH − High-Level Output Current − mA
Figure 3. Driver High-Level Output Voltage vs High-Level
Output Current
60
t PHL − High-To-Low Propagation Delay Time − ns
2.5
VCC = 3.3 V
TA = 25°C
3
2
1
0
−80
10
20
30
40
50
IOL − Low-Level Output Current − mA
Figure 4. Receiver Low-Level Output Voltage vs Low-Level
Output Current
4
VOH − High-Level Output Voltage − V
4
Figure 2. Driver Low-Level Output Voltage vs Low-Level
Output Current
3.5
−60
−40
−20
IOH − High-Level Output Current − mA
0
Figure 5. Receiver High-Level Output Voltage vs High-Level
Output Current
10
2
IOL − Low-Level Output Current − mA
Figure 1. Disabled Driver Output Current vs Output Voltage
VOH − High-Level Output Voltage − V
VCC = 3.3 V
TA = 25°C
Other output at 0 V
VOL − Low-Level Output Voltage − V
Disabled Driver Output Current − mA
40
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2
VCC = 3.3 V
VCC = 3 V
VCC = 3.6 V
1.5
−50
−30
10
−10
50
30
70
TA − Free-Air Temperature − °C
90
Figure 6. Driver High-to-Low Level Propagation Delay Time
vs Free-Air Temperature
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2.5
2
t PLH − High-To-Low Level Propagation Delay Time − ms
t PLH − Low-To-High Propagation Delay Time − ns
Typical Characteristics (continued)
VCC = 3.3 V
VCC = 3 V
VCC = 3.6 V
1.5
−50
−30
10
−10
50
30
70
TA − Free-Air Temperature − °C
90
t PLH − Low-To-High Level Propagation Delay Time − ns
Figure 7. Driver Low-to-High Level Propagation Delay Time
vs Free-Air Temperature
4.5
VCC = 3.3 V
4
VCC = 3 V
3.5
VCC = 3.6 V
3
2.5
−50
−30
10
−10
50
30
70
TA − Free−Air Temperature − °C
90
Figure 8. Receiver High-to-Low Level Propagation Delay
Time vs Free-Air Temperature
4.5
VCC = 3 V
4
VCC = 3.3 V
3.5
VCC = 3.6 V
3
2.5
−50
−30
10
−10
50
30
70
TA − Free-Air Temperature − °C
90
Figure 9. Receiver Low-to-High Level Propagation Delay Time vs Free-Air Temperature
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9 Parameter Measurement Information
9.1 Driver
Figure 10. Driver Voltage and Current Definitions
Driver Enable
Y
100 Ω
±1%
VOD
Input
Z
CL = 10 pF
(2 Places)
2V
1.4 V
0.8 V
Input
tPHL
tPLH
100%
80%
VOD(H)
Output
0V
VOD(L)
20%
0%
tf
A.
tr
All input pulses are supplied by a generator having the following characteristics: tr or tf ≤ 1 ns, pulse repetition rate
(PRR) = 50 Mpps, pulse width = 10 ± 0.2 ns. CL includes instrumentation and fixture capacitance within 0.06 mm of
the device under test.
Figure 11. Test Circuit, Timing, and Voltage Definitions for the Differential Output Signal
12
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Driver (continued)
49.9 Ω, ±1% (2 Places)
Driver Enable
3V
Y
0V
Input
Z
VOC
VOC(PP)
CL = 10 pF
(2 Places)
VOC(SS)
VOC
A.
All input pulses are supplied by a generator having the following characteristics: tr or tf ≤ 1 ns, pulse repetition rate
(PRR) = 50 Mpps, pulse width = 10 ± 0.2 ns. CL includes instrumentation and fixture capacitance within 0.06 mm of
the device under test. The measurement of VOC(PP) is made on test equipment with a –3-dB bandwidth of at least 300
MHz.
Figure 12. Test Circuit and Definitions for the Driver Common-Mode Output Voltage
49.9 W, ±1% (2 Places)
Y
0.8 V or 2 V
Z
DE
1.2 V
CL = 10 pF
(2 Places)
VOY
2V
1.4 V
0.8 V
DE
VOY or VOZ
ten
ten
~1.4 V
1.25 V
1.2 V
D at 2 V and input to DE
1.2 V
1.15 V
~1 V
D at 0.8 V and input to DE
tdis
VOZ or VOY
A.
VOZ
tdis
All input pulses are supplied by a generator having the following characteristics: tr or tf ≤ 1 ns, pulse repetition rate
(PRR) = 0.5 Mpps, pulse width = 500 ± 10 ns. CL includes instrumentation and fixture capacitance within 0.06 mm of
the device under test.
Figure 13. Enable or Disable Time Circuit and Definitions
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9.2 Receiver
A
V
IA
)V
IB
VID
2
R
VIA
B
VIC
VO
VIB
Figure 14. Receiver Voltage Definitions
Table 2. Receiver Minimum And Maximum Input Threshold Test Voltages
APPLIED VOLTAGES
14
RESULTING DIFFERENTIAL
INPUT VOLTAGE
RESULTING COMMON-MODE
INPUT VOLTAGE
VIA (V)
VIB (V)
VID (mV)
VIC (V)
1.25
1.15
100
1.2
1.15
1.25
–100
1.2
2.4
2.3
100
2.35
2.3
2.4
–100
2.35
0.1
0
100
0.05
0
0.1
–100
0.05
1.5
0.9
600
1.2
0.9
1.5
–600
1.2
2.4
1.8
600
2.1
1.8
2.4
–600
2.1
0.6
0
600
0.3
0
0.6
–600
0.3
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VIA
1.4 V
VIB
1V
VID
0.4 V
0V
–0.4 V
tPHL
VO
tPLH
VOH
2.4 V
1.4 V
0.4 V
VOL
tf
A.
tr
All input pulses are supplied by a generator having the following characteristics: tr or tf ≤ 1 ns, pulse repetition rate
(PRR) = 50 Mpps, pulse width = 10 ± 0.2 ns. CL includes instrumentation and fixture capacitance within 0.06 m of the
device under test.
Figure 15. Timing Test Circuit and Waveforms
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B
1.2 V
500 Ω
A
Inputs
CL
10 pF
RE
+
–
VO
VTEST
2.5 V
VTEST
A
1V
2V
1.4 V
RE
0.8 V
tPZL
tPZL
tPLZ
2.5 V
1.4 V
R
VOL +0.5 V
VOL
0V
VTEST
A
1.4 V
2V
RE
1.4 V
0.8 V
tPZH
R
tPZH
VOH –0.5 V
tPHZ
VOH
1.4 V
0V
A.
All input pulses are supplied by a generator having the following characteristics: tr or tf ≤ 1 ns, pulse repetition rate
(PRR) = 0.5 Mpps, pulse width = 500 ± 10 ns. CL includes instrumentation and fixture capacitance within 0.06 m of
the device under test.
Figure 16. Enable or Disable Time Test Circuit and Waveforms
16
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10 Detailed Description
10.1 Overview
The SN65LVDSxxx devices are single- and dual-channel LVDS line drivers and receivers. They operate from a
single supply that is nominally 3.3 V, but can be as low as 3.0 V and as high as 3.6 V.
The input signal to the drivers is an LVTTL signal. The output of the drivers is a differential signal complying with
the LVDS standard (TIA/EIA-644). The driver differential output signal operates with a signal level of 340 mV,
nominally, at a common-mode voltage of 1.2 V. This low differential output voltage results in a low emitted
radiated energy, which is dependent on the signal slew rate. The differential nature of the output provides
immunity to common-mode coupled signals that the driven signal may experience.
The SN65LVDSxxx devices are intended to drive a 100-Ω transmission line. This transmission line may be a
printed-circuit board (PCB) or cabled interconnect. With transmission lines, the optimum signal quality and power
delivery is reached when the transmission line is terminated with a load equal to the characteristic impedance of
the interconnect. Likewise, the driven 100-Ω transmission line should be terminated with a matched resistance.
The SN65LVDSxxx devices also include LVDS line receivers. The input signal to the receivers is a differential
LVDS signal. The output of the device is an LVTTL digital signal. This LVDS receivers require ±50 mV of input
signal to determine the correct state of the received signal. Compliant LVDS receivers can accept input signals
with a common-mode range between 0.025 V and 2.375 V. As the common-mode output voltage of an LVDS
driver is 1.2 V, the SN65LVDSxxx receivers correctly determine the line state when operated with a 1-V ground
shift between driver and receiver.
10.2 Functional Block Diagram
10.3 Feature Description
10.3.1 Driver Offset
An LVDS-compliant driver is required to maintain the common-mode output voltage at 1.2 V (±75 mV). The
SN65LVDSxxx drivers incorporate sense circuitry and a control loop to source common-mode current and keep
the output signal within specified values. Further, the device maintains the output common-mode voltage at this
set point over the full 3.0-V to 3.6-V supply range.
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Feature Description (continued)
10.3.2 5-V Input Tolerance
5-V and 3.3-V TTL logic standards share the same input high-voltage and input low-voltage thresholds, namely
2.0 V and 0.8 V, respectively. Although the maximum supply voltage for the SN65LVDSxxx is 3.6 V, the driver
can operate and meet all performance requirements when the input signals are as high as 5 V. This allows
operation with 3.3-V TTL as well as 5-V TTL logic. 3.3-V CMOS and 5-V CMOS inputs are also allowable,
although one should ensure that the duty-cycle distortion that will result from the TTL (ground-referenced)
thresholds are acceptable.
10.3.3 NC Pins
NC (not connected) pins are pins where the die is not physically connected to the lead frame or package. For
optimum thermal performance, a good rule of thumb is to ground the NC pins at the board level.
10.3.4 Driver Equivalent Schematics
The SN65LVDSxxx equivalent input and output schematic diagrams are shown in Figure 17. The driver input is
represented by a CMOS inverter stage with a 7-V Zener diode. The input stage is high-impedance, and includes
an internal pulldown to ground. If the driver input is left open, the driver input provides a low-level signal to the
rest of the driver circuitry, resulting in a low-level signal at the driver output pins. The Zener diode provides ESD
protection. The driver output stage is a differential pair, one half of which is shown in Figure 17. Like the input
stage, the driver output includes Zener diodes for ESD protection. The schematic shows an output stage that
includes a set of current sources (nominally 3.5 mA) that are connected to the output load circuit based upon the
input stage signal. To the first order, the SN65LVDSxxx output stage acts a constant-current source.
Figure 17. Equivalent Input and Output Schematic Diagrams
10.3.5 Receiver Features
10.3.5.1 Receiver Output States
When the receiver differential input signal is greater than 50 mV, the receiver output is high, and when the
differential input voltage is below –50 mV, the receiver output is low. When the input voltage is between these
thresholds (for example, between –50 mV and +50 mV), the receiver output is indeterminate. It may be high or
low. A special case occurs when the input to the receiver is open-circuited, which is covered in Receiver OpenCircuit Fail-Safe. When the receiver is disabled, the receiver outputs will be high-impedance.
10.3.5.2 Receiver Open-Circuit Fail-Safe
One of the most common problems with differential signaling applications is how the system responds when no
differential voltage is present on the signal pair. The LVDS receiver is like most differential line receivers in that
its output logic state can be indeterminate when the differential input voltage is between –100 mV and 100 mV
and within its recommended input common-mode voltage range. However, the SN65LVDSxxx receiver is
different in how it handles the open-input circuit situation.
18
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Feature Description (continued)
Open circuit means that there is little or no input current to the receiver from the data line itself. This could be
when the driver is in a high-impedance state or the cable is disconnected. When this occurs, the LVDS receiver
pulls each line of the signal to VCC through 300-kΩ resistors as shown in Figure 18. The fail-safe feature uses an
AND gate with input voltage thresholds at about 2.3 V to detect this condition and force the output to a high level.
VCC
300 kW
300 kW
A
Rt = 100 W(Typ)
Y
B
VIT ≈ 2.3 V
Figure 18. Open-Circuit Fail Safe of the LVDS Receiver
It is only under these conditions that the output of the receiver is valid with less than a 100-mV differential input
voltage magnitude. The presence of the termination resistor, Rt does not affect the fail-safe function as long as it
is connected as shown in Figure 18. Other termination circuits may allow a dc current to ground that could defeat
the pullup currents from the receiver and the fail-safe feature.
10.3.5.3 Receiver Power-On Reset
The SN65LVDSxxx receivers include power-on reset circuitry. When the supply voltage drops below 1.5 V (or is
turning on and has not yet reached 1.5 V), power-on reset circuitry sets the receiver input pins to a highimpedance state.
10.3.5.4 Common-Mode Range vs Supply Voltage
The SN65LVDSxxx receivers operate over an input common-mode range from VID/2 V to (2.4 – VID/2) V. Hence,
if the input signal is a minimum differential voltage of 50 mV, common-mode values in the range of 0.025 V to
2.375 V are supported.
10.3.5.5 General Purpose Comparator
While the SN65LVDSxxx are LVDS standard-compliant receivers, their utility and applications extend to a wider
range of signals. As long as the input signals are within the required differential and common-mode voltage
ranges mentioned above, the receiver output will be a faithful representation of the input signal.
10.3.5.6 Receiver Equivalent Schematics
The SN65LVDSxxx receiver equivalent input and output schematic diagrams are shown in Figure 19. The
receiver input is a high-impedance differential pair. 7-V Zener diodes are included on each input to provide ESD
protection. The receiver output structure shown is a CMOS inverter with an additional Zener diode, again for ESD
protection.
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Feature Description (continued)
Figure 19. Equivalent Input and Output Schematic Diagrams
10.4 Device Functional Modes
10.4.1 Function Tables
Table 3. SN65LVDS179 Receiver
(1)
INPUTS
OUTPUT (1)
VID = VA – VB
R
VID ≥ 100 mV
H
–100 mV < VID < 100 mV
?
VID ≤ –100 mV
L
Open
H
H = high level, L = low level, ? = indeterminate
Table 4. SN65LVDS179 Driver (1)
INPUT
(1)
OUTPUTS
D
Y
Z
L
L
H
H
H
L
Open
L
H
H = high level, L = low level
Table 5. SN65LVDS180, SN65LVDS050, and
SN65LVDS051 Receivers (1)
INPUTS
(1)
20
OUTPUT
VID = VA – VB
RE
R
VID ≥ 100 mV
L
H
–100 mV < VID < 100 mV
L
?
VID ≤ –100 mV
L
L
Open
L
H
X
H
Z
H = high level, L = low level, Z = high-impedance, X = don't care,
? = indeterminate
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Table 6. SN65LVDS180, SN65LVDS050, and
SN65LVDS051 Drivers (1)
INPUTS
(1)
OUTPUTS
D
DE
Y
Z
L
H
L
H
H
H
H
L
Open
H
L
H
X
L
Off
Off
H = high level, L = low level, Z = high-impedance, X = don't care, Off
= no output
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11 Application and Implementation
NOTE
Information in the following applications sections is not part of the TI component
specification, and TI does not warrant its accuracy or completeness. TI’s customers are
responsible for determining suitability of components for their purposes. Customers should
validate and test their design implementation to confirm system functionality.
11.1 Application Information
The SNx5LVDSxx are LVDS drivers and receivers. These devices are generally used as building blocks for highspeed, point-to-point, data transmission where ground differences are less than 1 V. LVDS drivers and receivers
provide high-speed signaling rates that are often implemented with ECL class devices without the ECL power
and dual-supply requirements.
11.2 Typical Application
The most basic application for LVDS buffers, as found in this data sheet, is for point-to-point communications of
digital data, as shown in Figure 20.
IN+
OUT+
Driver
Receiver
100
IN-
OUT-
Figure 20. Point-to-Point Topology
A point-to-point communications channel has a single transmitter (driver) and a single receiver. This
communications topology is often referred to as simplex. In Figure 20 the driver receives a single-ended input
signal and the receiver outputs a single-ended recovered signal. The LVDS driver converts the single-ended
input to a differential signal for transmission over a balanced interconnecting media of 100-Ω characteristic
impedance. The conversion from a single-ended signal to an LVDS signal retains the digital data payload while
translating to a signal whose features are more appropriate for communication over extended distances or in a
noisy environment.
11.2.1 Design Requirements
DESIGN PARAMETERS
EXAMPLE VALUE
Driver Supply Voltage (VCCD)
3.0 to 3.6 V
Driver Input Voltage
0.8 to 3.3 V
Driver Signaling Rate
DC to 100 Mbps
Interconnect Characteristic Impedance
100 Ω
Termination Resistance
100 Ω
Number of Receiver Nodes
1
Receiver Supply Voltage (VCCR)
3.0 to 3.6 V
Receiver Input Voltage
0 to 2.4 V
Receiver Signaling Rate
DC to 100 Mbps
Ground shift between driver and receiver
±1 V
11.2.2 Detailed Design Procedure
11.2.2.1 Equipment
•
•
•
22
Hewlett Packard HP6624A DC power supply
Tektronix TDS7404 Real Time Scope
Agilent ParBERT E4832A
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Hewlett Packard HP6624A
DC Power Supply
Agilent ParBERT
(E4832A)
Bench Test Board
Tektronix TDS7404
Real Time Scope
Figure 21. Equipment Setup
11.2.2.2 Driver Supply Voltage
An LVDS driver is operated from a single supply. The device can support operation with a supply as low as 3 V
and as high as 3.6 V. The differential output voltage is nominally 340 mV over the complete output range. The
minimum output voltage stays within the specified LVDS limits (247 mV to 454 mV) for the complete 3-V to 3.6-V
supply range.
11.2.2.3 Driver Bypass Capacitance
Bypass capacitors play a key role in power distribution circuitry. Specifically, they create low-impedance paths
between power and ground. At low frequencies, a good digital power supply offers very-low-impedance paths
between its terminals. However, as higher frequency currents propagate through power traces, the source is
quite often incapable of maintaining a low-impedance path to ground. Bypass capacitors are used to address this
shortcoming. Usually, large bypass capacitors (10 to 1000 μF) at the board-level do a good job up into the kHz
range. Due to their size and length of their leads, they tend to have large inductance values at the switching
frequencies of modern digital circuitry. To solve this problem, one should resort to the use of smaller capacitors
(nF to μF range) installed locally next to the integrated circuit.
Multilayer ceramic chip or surface-mount capacitors (size 0603 or 0805) minimize lead inductances of bypass
capacitors in high-speed environments, because their lead inductance is about 1 nH. For comparison purposes,
a typical capacitor with leads has a lead inductance around 5 nH.
The value of the bypass capacitors used locally with LVDS chips can be determined by the following formula
according to Johnson (1), equations 8.18 to 8.21. A conservative rise time of 200 ps and a worst-case change in
supply current of 1 A covers the whole range of LVDS devices offered by Texas Instruments. In this example, the
maximum power supply noise tolerated is 200 mV; however, this figure varies depending on the noise budget
available in your design. (1)
æ DIMaximum Step Change Supply Current ö
Cchip = ç
÷ ´ TRise Time
è DVMaximum Power Supply Noise ø
(1)
æ 1A ö
CLVDS = ç
÷ ´ 200 ps = 0.001 mF
è 0.2V ø
(2)
The following example lowers lead inductance and covers intermediate frequencies between the board-level
capacitor (>10 µF) and the value of capacitance found above (0.001 µF). You should place the smallest value of
capacitance as close as possible to the chip.
(1)
Howard Johnson & Martin Graham.1993. High Speed Digital Design – A Handbook of Black Magic. Prentice Hall PRT. ISBN number
013395724.
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3.3 V
0.1 µF
0.001 µF
Figure 22. Recommended LVDS Bypass Capacitor Layout
11.2.2.4 Driver Output Voltage
The LVDS driver output is a 1.2-V common-mode voltage, with a nominal differential output signal of 340 mV.
This 340 mV is the absolute value of the differential swing (VOD = |V+ – V–|). The peak-to-peak differential voltage
is twice this value, or 680 mV.
11.2.2.5 Interconnecting Media
The physical communication channel between the driver and the receiver may be any balanced paired metal
conductors meeting the requirements of the LVDS standard, the key points which will be included here. This
media may be a twisted pair, twinax, flat ribbon cable, or PCB traces.
The nominal characteristic impedance of the interconnect should be between 100 Ω and 120 Ω with variation no
more than 10% (90 Ω to 132 Ω).
11.2.2.6 PCB Transmission Lines
As per SNLA187, Figure 23 depicts several transmission line structures commonly used in printed-circuit boards
(PCBs). Each structure consists of a signal line and a return path with uniform cross-section along its length. A
microstrip is a signal trace on the top (or bottom) layer, separated by a dielectric layer from its return path in a
ground or power plane. A stripline is a signal trace in the inner layer, with a dielectric layer in between a ground
plane above and below the signal trace. The dimensions of the structure along with the dielectric material
properties determine the characteristic impedance of the transmission line (also called controlled-impedance
transmission line).
When two signal lines are placed close by, they form a pair of coupled transmission lines. Figure 23 shows
examples of edge-coupled microstrips, and edge-coupled or broad-side-coupled striplines. When excited by
differential signals, the coupled transmission line is referred to as a differential pair. The characteristic impedance
of each line is called odd-mode impedance. The sum of the odd-mode impedances of each line is the differential
impedance of the differential pair. In addition to the trace dimensions and dielectric material properties, the
spacing between the two traces determines the mutual coupling and impacts the differential impedance. When
the two lines are immediately adjacent; for example, S is less than 2W, the differential pair is called a tightlycoupled differential pair. To maintain constant differential impedance along the length, it is important to keep the
trace width and spacing uniform along the length, as well as maintain good symmetry between the two lines.
Single-Ended Microstrip
Single-Ended Stripline
W
W
T
H
T
H
§ 5.98 H ·
ln ¨
¸
1.41 © 0.8 W T ¹
87
Z0
Hr
H
Z0
Edge-Coupled
60
Hr
§ 1.9 > 2 H T @ ·
ln ¨
¨ >0.8 W T @ ¸¸
©
¹
Edge-Coupled
S
S
H
H
Differential Microstrip
Zdiff
§
2 u Z0 u ¨ 1 0.48 u e
¨
©
Differential Stripline
0.96 u
s
H
·
¸
¸
¹
Zdiff
Co-Planar Coupled
Microstrips
W
G
2.9 u
s
H
·
¸
¸
¹
Broad-Side Coupled
Striplines
W
S
§
2 u Z0 u ¨ 1 0.347e
¨
©
W
G
S
H
H
Figure 23. Controlled-Impedance Transmission Lines
24
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11.2.2.7 Termination Resistor
An LVDS communication channel employs a current source driving a transmission line which is terminated with a
resistive load. This load serves to convert the transmitted current into a voltage at the receiver input. To ensure
incident wave switching (which is necessary to operate the channel at the highest signaling rate), the termination
resistance should be matched to the characteristic impedance of the transmission line. The designer should
ensure that the termination resistance is within 10% of the nominal media characteristic impedance. If the
transmission line is targeted for 100-Ω impedance, the termination resistance should be between 90 and 110 Ω.
The line termination resistance should be located as close as possible to the receiver, thereby minimizing the
stub length from the resistor to the receiver. The limiting case would be to incorporate the termination resistor
into the receiver, which is exactly what is offered with the TI ‘LVDT receivers.
While we talk in this section about point-to-point communications, a word of caution is useful when a multidrop
topology is used. In such topologies, line termination resistors are to be located only at the end(s) of the
transmission line. In such an environment, LVDS receivers could be used for loads branching off the main bus,
with an LVDT receiver used only at the bus end.
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www.ti.com
11.2.3 Application Curves
Unless otherwise specified: T = 25°C; VCC = 3.6 V; PRBS = 223 – 1
Tx + Rx running at 150 Mbps; Channel 1: R, Channel 2: Y-Z
Figure 24. Typical Eye Pattern SN65LVDS179: Tx + Rx
Tx only running at 400 Mbps; Channel 1: Y-Z
Figure 26. Typical Eye Pattern SN65LVDS179: Tx
Rx only running at 150 Mbps; Channel 1: R
Figure 28. Typical Eye Pattern SN65LVDS180: Rx
26
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Rx only running at 150 Mbps; Channel 1: R
Figure 25. Typical Eye Pattern SN65LVDS179: Rx
Tx + Rx running at 150 Mbps; Channel 1: R, Channel 2: Y-Z
Figure 27. Typical Eye Pattern SN65LVDS180: Tx + Rx
Tx only running at 400 Mbps; Channel 1: Y-Z
Figure 29. Typical Eye Pattern SN65LVDS180: Tx
Copyright © 1998–2016, Texas Instruments Incorporated
Product Folder Links: SN65LVDS179 SN65LVDS180 SN65LVDS050 SN65LVDS051
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www.ti.com
SLLS301R – APRIL 1998 – REVISED JANUARY 2016
Unless otherwise specified: T = 25°C; VCC = 3.6 V; PRBS = 223 – 1
All buffers running at 100 Mbps; Channel 1: R, Channel 2: 2R,
Channel 3: 1Y-1Z, Channel 4: 2Y-2Z
Figure 30. Typical Eye Pattern SN65LVDS050: All Buffers
Tx buffers only running at 400 Mbps; Channel 3: 1Y-1Z,
Channel 4: 2Y-2Z
Figure 32. Typical Eye Pattern SN65LVDS050: Tx Buffers
Rx buffers only running at 100 Mbps; Channel 1: R,
Channel 2: 2R
Figure 34. Typical Eye Pattern SN65LVDS051: Rx Buffers
Copyright © 1998–2016, Texas Instruments Incorporated
Rx buffers only running at 100 Mbps; Channel 1: R,
Channel 2: 2R
Figure 31. Typical Eye Pattern SN65LVDS050: Rx Buffers
All buffers running at 100 Mbps; Channel 1: R, Channel 2: 2R,
Channel 3: 1Y-1Z, Channel 4: 2Y-2Z
Figure 33. Typical Eye Pattern SN65LVDS051: All Buffers
Tx buffers only running at 400 Mbps; Channel 3: 1Y-1Z,
Channel 4: 2Y-2Z
Figure 35. Typical Eye Pattern SN65LVDS051: Tx Buffers
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www.ti.com
12 Power Supply Recommendations
The LVDS driver and receivers in this data sheet are designed to operate from a single power supply. Both
drivers and receivers operate with supply voltages in the range of 3.0 V to 3.6 V. In a typical application, a driver
and a receiver may be on separate boards, or even separate equipment. In these cases, separate supplies
would be used at each location. The expected ground potential difference between the driver power supply and
the receiver power supply would be less than |±1 V|. Board level and local device level bypass capacitance
should be used and are covered in Driver Bypass Capacitance.
13 Layout
13.1 Layout Guidelines
13.1.1 Microstrip vs. Stripline Topologies
As per SLLD009, printed-circuit boards usually offer designers two transmission line options: Microstrip and
stripline. Microstrips are traces on the outer layer of a PCB, as shown in Figure 36.
Figure 36. Microstrip Topology
On the other hand, striplines are traces between two ground planes. Striplines are less prone to emissions and
susceptibility problems because the reference planes effectively shield the embedded traces. However, from the
standpoint of high-speed transmission, juxtaposing two planes creates additional capacitance. TI recommends
routing LVDS signals on microstrip transmission lines, if possible. The PCB traces allow designers to specify the
necessary tolerances for ZO based on the overall noise budget and reflection allowances. Footnotes 1 (1), 2 (2),
and 3 (3) provide formulas for ZO and tPD for differential and single-ended traces. (1) (2) (3)
Figure 37. Stripline Topology
13.1.2 Dielectric Type and Board Construction
The speeds at which signals travel across the board dictates the choice of dielectric. FR-4, or equivalent, usually
provides adequate performance for use with LVDS signals. If rise or fall times of TTL/CMOS signals are less
than 500 ps, empirical results indicate that a material with a dielectric constant near 3.4, such as Rogers™ 4350
or Nelco N4000-13 is better suited. Once the designer chooses the dielectric, there are several parameters
pertaining to the board construction that can affect performance. The following set of guidelines were developed
experimentally through several designs involving LVDS devices:
• Copper weight: 15 g or 1/2 oz start, plated to 30 g or 1 oz
• All exposed circuitry should be solder-plated (60/40) to 7.62 μm or 0.0003 in (minimum).
(1)
(2)
(3)
28
Howard Johnson & Martin Graham.1993. High Speed Digital Design – A Handbook of Black Magic. Prentice Hall PRT. ISBN number
013395724.
Mark I. Montrose. 1996. Printed Circuit Board Design Techniques for EMC Compliance. IEEE Press. ISBN number 0780311310.
Clyde F. Coombs, Jr. Ed, Printed Circuits Handbook, McGraw Hill, ISBN number 0070127549.
Submit Documentation Feedback
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SLLS301R – APRIL 1998 – REVISED JANUARY 2016
Layout Guidelines (continued)
•
•
Copper plating should be 25.4 μm or 0.001 in (minimum) in plated-through-holes.
Solder mask over bare copper with solder hot-air leveling
13.1.3 Recommended Stack Layout
Following the choice of dielectrics and design specifications, you should decide how many levels to use in the
stack. To reduce the TTL/CMOS to LVDS crosstalk, it is a good practice to have at least two separate signal
planes as shown in Figure 38.
Layer 1: Routed Plane (LVDS Signals)
Layer 2: Ground Plane
Layer 3: Power Plane
Layer 4: Routed Plane (TTL/CMOS Signals)
Figure 38. Four-Layer PCB Board
NOTE
The separation between layers 2 and 3 should be 127 μm (0.005 in). By keeping the
power and ground planes tightly coupled, the increased capacitance acts as a bypass for
transients.
One of the most common stack configurations is the six-layer board, as shown in Figure 39.
Layer 1: Routed Plane (LVDS Signals)
Layer 2: Ground Plane
Layer 3: Power Plane
Layer 4: Ground Plane
Layer 5: Ground Plane
Layer 4: Routed Plane (TTL Signals)
Figure 39. Six-Layer PCB Board
In this particular configuration, it is possible to isolate each signal layer from the power plane by at least one
ground plane. The result is improved signal integrity; however, fabrication is more expensive. Using the 6-layer
board is preferable, because it offers the layout designer more flexibility in varying the distance between signal
layers and referenced planes, in addition to ensuring reference to a ground plane for signal layers 1 and 6.
13.1.4 Separation Between Traces
The separation between traces depends on several factors; however, the amount of coupling that can be
tolerated usually dictates the actual separation. Low-noise coupling requires close coupling between the
differential pair of an LVDS link to benefit from the electromagnetic field cancellation. The traces should be 100-Ω
differential and thus coupled in the manner that best fits this requirement. In addition, differential pairs should
have the same electrical length to ensure that they are balanced, thus minimizing problems with skew and signal
reflection.
In the case of two adjacent single-ended traces, one should use the 3-W rule, which stipulates that the distance
between two traces should be greater than two times the width of a single trace, or three times its width
measured from trace center to trace center. This increased separation effectively reduces the potential for
crosstalk. The same rule should be applied to the separation between adjacent LVDS differential pairs, whether
the traces are edge-coupled or broad-side-coupled.
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www.ti.com
Layout Guidelines (continued)
W
LVDS
Pair
Differential Traces
S=
Minimum spacing as
defined by PCB vendor
W
t2W
Single-Ended Traces
TTL/CMOS
Trace
W
Figure 40. 3-W Rule for Single-Ended and Differential Traces (Top View)
You should exercise caution when using autorouters, because they do not always account for all factors affecting
crosstalk and signal reflection. For instance, it is best to avoid sharp 90° turns to prevent discontinuities in the
signal path. Using successive 45° turns tends to minimize reflections.
13.1.5 Crosstalk and Ground Bounce Minimization
To reduce crosstalk, it is important to provide a return path to high-frequency currents that is as close as possible
to its originating trace. A ground plane usually achieves this. Because the returning currents always choose the
path of lowest inductance, they are most likely to return directly under the original trace, thus minimizing
crosstalk. Lowering the area of the current loop lowers the potential for crosstalk. Traces kept as short as
possible with an uninterrupted ground plane running beneath them emit the minimum amount of electromagnetic
field strength. Discontinuities in the ground plane increase the return path inductance and should be avoided.
13.2 Layout Example
At least two or three times the width of an individual trace should separate single-ended traces and differential
pairs to minimize the potential for crosstalk. Single-ended traces that run in parallel for less than the wavelength
of the rise or fall times usually have negligible crosstalk. Increase the spacing between signal paths for long
parallel runs to reduce crosstalk. Boards with limited real estate can benefit from the staggered trace layout, as
shown in Figure 41.
Layer 1
Layer 6
Figure 41. Staggered Trace Layout
This configuration lays out alternating signal traces on different layers; thus, the horizontal separation between
traces can be less than 2 or 3 times the width of individual traces. To ensure continuity in the ground signal path,
TI recommends having an adjacent ground via for every signal via, as shown in Figure 42. Note that vias create
additional capacitance. For example, a typical via has a lumped capacitance effect of 1/2 pF to 1 pF in FR4.
Signal Via
Signal Trace
Uninterrupted Ground Plane
Signal Trace
Uninterrupted Ground Plane
Ground Via
Figure 42. Ground Via Location (Side View)
30
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SLLS301R – APRIL 1998 – REVISED JANUARY 2016
Layout Example (continued)
Short and low-impedance connection of the device ground pins to the PCB ground plane reduces ground
bounce. Holes and cutouts in the ground planes can adversely affect current return paths if they create
discontinuities that increase returning current loop areas.
To minimize EMI problems, TI recommends avoiding discontinuities below a trace (for example, holes, slits, and
so on) and keeping traces as short as possible. Zoning the board wisely by placing all similar functions in the
same area, as opposed to mixing them together, helps reduce susceptibility issues.
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www.ti.com
14 Device and Documentation Support
14.1 Device Support
14.1.1 Third-Party Products Disclaimer
TI'S PUBLICATION OF INFORMATION REGARDING THIRD-PARTY PRODUCTS OR SERVICES DOES NOT
CONSTITUTE AN ENDORSEMENT REGARDING THE SUITABILITY OF SUCH PRODUCTS OR SERVICES
OR A WARRANTY, REPRESENTATION OR ENDORSEMENT OF SUCH PRODUCTS OR SERVICES, EITHER
ALONE OR IN COMBINATION WITH ANY TI PRODUCT OR SERVICE.
14.1.2 Other LVDS Products
For other products and application notes in the LVDS and LVDM product families visit our Web site at
http://www.ti.com/sc/datatran.
14.2 Documentation Support
14.2.1 Related Information
IBIS modeling is available for this device. Contact the local TI sales office or the TI Web site at www.ti.com for
more information.
For more application guidelines, see the following documents:
• Low-Voltage Differential Signaling Design Notes (SLLA014)
• Interface Circuits for TIA/EIA-644 (LVDS) (SLLA038)
• Reducing EMI With LVDS (SLLA030)
• Slew Rate Control of LVDS Circuits (SLLA034)
• Using an LVDS Receiver With RS-422 Data (SLLA031)
• Evaluating the LVDS EVM (SLLA033)
14.3 Related Links
Table 7 lists quick access links. Categories include technical documents, support and community resources,
tools and software, and quick access to sample or buy.
Table 7. Related Links
PARTS
PRODUCT FOLDER
SAMPLE & BUY
TECHNICAL
DOCUMENTS
TOOLS &
SOFTWARE
SUPPORT &
COMMUNITY
SN65LVDS179
Click here
Click here
Click here
Click here
Click here
SN65LVDS180
Click here
Click here
Click here
Click here
Click here
SN65LVDS050
Click here
Click here
Click here
Click here
Click here
SN65LVDS051
Click here
Click here
Click here
Click here
Click here
14.4 Trademarks
Rogers is a trademark of Rogers Corporation.
All other trademarks are the property of their respective owners.
14.5 Electrostatic Discharge Caution
These devices have limited built-in ESD protection. The leads should be shorted together or the device placed in conductive foam
during storage or handling to prevent electrostatic damage to the MOS gates.
14.6 Glossary
SLYZ022 — TI Glossary.
This glossary lists and explains terms, acronyms, and definitions.
32
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SLLS301R – APRIL 1998 – REVISED JANUARY 2016
15 Mechanical, Packaging, and Orderable Information
The following pages include mechanical, packaging, and orderable information. This information is the most
current data available for the designated devices. This data is subject to change without notice and revision of
this document. For browser-based versions of this data sheet, refer to the left-hand navigation.
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33
PACKAGE OPTION ADDENDUM
www.ti.com
14-Oct-2022
PACKAGING INFORMATION
Orderable Device
Status
(1)
Package Type Package Pins Package
Drawing
Qty
Eco Plan
(2)
Lead finish/
Ball material
MSL Peak Temp
Op Temp (°C)
Device Marking
(3)
Samples
(4/5)
(6)
SN65LVDS050D
ACTIVE
SOIC
D
16
40
RoHS & Green
NIPDAU
Level-1-260C-UNLIM
-40 to 85
LVDS050
Samples
SN65LVDS050DG4
ACTIVE
SOIC
D
16
40
RoHS & Green
NIPDAU
Level-1-260C-UNLIM
-40 to 85
LVDS050
Samples
SN65LVDS050DR
ACTIVE
SOIC
D
16
2500
RoHS & Green
NIPDAU
Level-1-260C-UNLIM
-40 to 85
LVDS050
Samples
SN65LVDS050PW
ACTIVE
TSSOP
PW
16
90
RoHS & Green
NIPDAU
Level-1-260C-UNLIM
LVDS050
Samples
SN65LVDS050PWR
ACTIVE
TSSOP
PW
16
2000
RoHS & Green
NIPDAU
Level-1-260C-UNLIM
LVDS050
Samples
SN65LVDS051D
ACTIVE
SOIC
D
16
40
RoHS & Green
NIPDAU
Level-1-260C-UNLIM
-40 to 85
LVDS051
Samples
SN65LVDS051DR
ACTIVE
SOIC
D
16
2500
RoHS & Green
NIPDAU
Level-1-260C-UNLIM
-40 to 85
LVDS051
Samples
SN65LVDS051PW
ACTIVE
TSSOP
PW
16
90
RoHS & Green
NIPDAU
Level-1-260C-UNLIM
-40 to 85
LVDS051
Samples
SN65LVDS051PWR
ACTIVE
TSSOP
PW
16
2000
RoHS & Green
NIPDAU
Level-1-260C-UNLIM
-40 to 85
LVDS051
Samples
SN65LVDS179D
ACTIVE
SOIC
D
8
75
RoHS & Green
NIPDAU
Level-1-260C-UNLIM
-40 to 85
DL179
Samples
SN65LVDS179DGK
ACTIVE
VSSOP
DGK
8
80
RoHS & Green
NIPDAU
Level-1-260C-UNLIM
-40 to 85
S79
Samples
SN65LVDS179DGKG4
ACTIVE
VSSOP
DGK
8
80
RoHS & Green
NIPDAU
Level-1-260C-UNLIM
-40 to 85
S79
Samples
SN65LVDS179DGKR
ACTIVE
VSSOP
DGK
8
2500
RoHS & Green
NIPDAU
Level-1-260C-UNLIM
-40 to 85
S79
Samples
SN65LVDS179DR
ACTIVE
SOIC
D
8
2500
RoHS & Green
NIPDAU
Level-1-260C-UNLIM
-40 to 85
DL179
Samples
SN65LVDS180D
ACTIVE
SOIC
D
14
50
RoHS & Green
NIPDAU
Level-1-260C-UNLIM
-40 to 85
LVDS180
Samples
SN65LVDS180DG4
ACTIVE
SOIC
D
14
50
RoHS & Green
NIPDAU
Level-1-260C-UNLIM
-40 to 85
LVDS180
Samples
SN65LVDS180DR
ACTIVE
SOIC
D
14
2500
RoHS & Green
NIPDAU
Level-1-260C-UNLIM
-40 to 85
LVDS180
Samples
SN65LVDS180DRG4
ACTIVE
SOIC
D
14
2500
RoHS & Green
NIPDAU
Level-1-260C-UNLIM
-40 to 85
LVDS180
Samples
SN65LVDS180PW
ACTIVE
TSSOP
PW
14
90
RoHS & Green
NIPDAU
Level-1-260C-UNLIM
-40 to 85
LVDS180
Samples
SN65LVDS180PWR
ACTIVE
TSSOP
PW
14
2000
RoHS & Green
NIPDAU
Level-1-260C-UNLIM
-40 to 85
LVDS180
Samples
Addendum-Page 1
PACKAGE OPTION ADDENDUM
www.ti.com
Orderable Device
14-Oct-2022
Status
(1)
Package Type Package Pins Package
Drawing
Qty
Eco Plan
(2)
Lead finish/
Ball material
RoHS & Green
NIPDAU
MSL Peak Temp
Op Temp (°C)
Device Marking
(3)
Samples
(4/5)
(6)
SN65LVDS180PWRG4
ACTIVE
TSSOP
PW
14
2000
Level-1-260C-UNLIM
-40 to 85
LVDS180
(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)
RoHS: TI defines "RoHS" to mean semiconductor products that are compliant with the current EU RoHS requirements for all 10 RoHS substances, including the requirement that RoHS substance
do not exceed 0.1% by weight in homogeneous materials. Where designed to be soldered at high temperatures, "RoHS" products are suitable for use in specified lead-free processes. TI may
reference these types of products as "Pb-Free".
RoHS Exempt: TI defines "RoHS Exempt" to mean products that contain lead but are compliant with EU RoHS pursuant to a specific EU RoHS exemption.
Green: TI defines "Green" to mean the content of Chlorine (Cl) and Bromine (Br) based flame retardants meet JS709B low halogen requirements of
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