High Power TVS for
Ethernet Interfaces
PROTECTION PRODUCTS - RailClamp
®
Description
RailClamp
®
TVS diodes are specifically designed to
protect sensitive components which are connected to
high-speed data and transmission lines from overvolt-
age caused by ESD (electrostatic discharge), CDE
(cable discharge events), and EFT (electrical fast
transients).
The unique design incorporates surge rated, low
capacitance steering diodes and a TVS diode in a
single package. The RClamp
®
2574N is designed to
replace up to two components for board level GbE
protection. Each device is designed to protect two line
pairs. This is accomplished by routing traces through
the device. When connected in this fashion, the device
can withstand a high level of surge current (40A, 8/
20us) while maintaining a low loading capacitance of
less than 5pF. The high surge capability means it can
be used in high threat environments in applications
such as Gigabit Ethernet, telecommunication lines, and
LVDS interfaces.
The RClamp
®
2574N is constructed using Semtech’s
proprietary EPD process technology. The EPD process
provides low stand-off voltages with significant reduc-
tions in leakage current and capacitance over silicon-
avalanche diode processes. It features a true operat-
ing voltage of 2.5 volts for superior protection.
The RClamp2574N is in a 10-pin SLP3020N10 pack-
age. It measures 3.0 x 2.0 x 0.60mm. The leads are
finished with lead-free NiPdAu.
RClamp2574N
Features
Transient protection for high-speed data lines to
IEC 61000-4-2 (ESD) ±30kV (air), ±30kV (contact)
IEC 61000-4-4 (EFT) 40A (5/50ns)
IEC 61000-4-5 (Lightning) 40A (8/20μs)
Array of surge rated diodes with internal TVS Diode
Small package saves board space
Protects two line pairs
Low capacitance for high-speed interfaces
Low variation in capacitance vs. bias voltage
Low clamping voltage
Low operating voltage: 2.5V
Solid-state silicon-avalanche technology
Mechanical Characteristics
SLP3020N10 10L package
Pb-Free, Halogen Free, RoHS/WEEE Compliant
Nominal Dimensions: 3.0 x 2.0 x 0.60 mm
Lead Finish: NiPdAu
Molding compound flammability rating: UL 94V-0
Marking : Marking code + Date code
Packaging : Tape and Reel
Applications
10/100/1000 Ethernet
Central Office Equipment
LVDS Interfaces
MagJacks / Integrated Magnetics
Notebooks / Desktops / Servers
Schematic
Pin 1
LINE 1 In
Pin 4
LINE 3 In
Pin Configuration
Line 1 In
1
GND
Line 2 In
Pin 10
LINE 1 Out
Pin 2
LINE 2 In
Pin 7
LINE 3 Out
Pin 5
LINE 4 In
10
Line 1 Out
Line 2 Out
GND
Line 3 In
GND
GND
Line 3 Out
GND
Line 4 In
5
Pin 9
LINE 2 Out
Center Tabs
and Pins 3, 8
Pin 6
LINE 4 Out
6
Line 4 Out
Top View
1
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Revision 10/20/2010
RClamp2574N
PROTECTION PRODUCTS
Absolute Maximum Rating
R ating
Peak Pulse Power (tp = 8/20
μ
s)
1
Peak Pulse Current (tp = 8/20
μ
s)
1
ESD p er IEC 61000-4-2 (Air)
ESD p er IEC 61000-4-2 (Contact)
Op erating Temp erature
Storage Temp erature
Symbol
P
p k
I
P P
V
ESD
T
J
T
STG
Value
1000
40
+/-30
+/-30
-55 to +85
-55 to +150
Units
Watts
A
kV
°C
°C
Electrical Characteristics (T=25
o
C)
Parameter
Reverse Stand-Off Voltage
Punch-Through Voltage
Snap-Back Voltage
Reverse Leakage Current
Clamping Voltage
Clamping Voltage
2
Clamping Voltage
2
Clamping Voltage
1,2
Symbol
V
RWM
V
PT
V
SB
I
R
V
C
V
C
V
C
V
C
I
PT
= 2
μ
A
I
SB
= 50mA
V
RWM
= 2.5V, T=25°C
I
PP
= 1A, t
p
= 8/20
μ
s
Any I/O to Ground
I
PP
= 10A, t
p
= 8/20
μ
s
Any 1 I/O to Ground
I
PP
= 25A, t
p
= 8/20
μ
s
Any I/O to Ground
I
PP
= 40A, t
p
= 8/20
μ
s
Line-to-Line, two I/O pins
connected together on each
line (N ote 1)
V
R
= 0V, f = 1MHz
Any I/O to Ground
V
R
= 0V, f = 1MHz
Between I/O pins
3.75
1.7
2.7
2.0
0.5
4.5
7.5
12
20
Conditions
Minimum
Typical
Maximum
2.5
Units
V
V
V
μ
A
V
V
V
V
Junction Capacitance
2
C
j
5
pF
pF
Notes:
1) Ratings with 2 pins connected together per the recommended configuration (ie pin 1 connected to pin 10, pin 2 connected to pin 9, pin 4
connected to pin 7, and pin 5 connected to pin 6).
2) Guaranteed by design (not production tested)
©
2010 Semtech Corp.
2
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RClamp2574N
PROTECTION PRODUCTS
Typical Characteristics
Non-Repetitive Peak Pulse Power vs. Pulse Time
10
120
100
% of Rated Power or I
PP
Power Derating Curve
Peak Pulse Power - P
PP
(kW)
80
60
40
20
1
0.1
0.1
1
10
Pulse Duration - tp (us)
100
1000
0
0
25
50
Ambient Temperature - TA ( C)
o
75
100
Surge Current Output Waveform
(tp = 8/20us)
110
100
90
80
Percent of I
PP
70
60
50
40
30
20
10
0
0
5
10
15
Time (µs)
20
25
30
td = I
PP
/2
e
-t
Clamping Voltage vs. Peak Pulse Current
Any I/O to GND (tp = 8/20us)
9
8
Clamping Voltage -V
C
(V)
7
6
5
4
3
2
1
0
0
5
10
15
20
25
30
Waveform
Parameters:
tr = 8µs
td = 20µs
Waveform
Parameters:
tr = 8µs
td = 20µs
Peak Pulse Current - I
PP
(A)
Clamping Voltage vs. Peak Pulse Current
Line-to-Line, two I/O pins connected together on
each line (tp = 8/20us)
24
Normalized Capacitance vs. Reverse Voltage
1.5
1.4
19
Clamping Voltage -Vc (V)
Cj(V
R
) / Cj(V
R
=0V)
1.3
1.2
14
1.1
1
0.9
0.8
9
Waveform
Parameters:
tr = 8µs
td = 20µs
0
10
20
30
40
50
4
0.7
0.6
0.5
0
0.5
1
1.5
2
2.5
f = 1 MHz
-1
Peak Pulse Current - Ipp (A)
Reverse Voltage (V
R
)
©
2010 Semtech Corp.
3
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RClamp2574N
PROTECTION PRODUCTS
Typical Characteristics
Insertion Loss S21 (I/O to Gnd)
CH1 S21
LOG
6 dB / REF 0 dB
1: - 1.7540 dB
800 MHz
0 dB
1
Insertion Loss S21 (I/O to I/O)
CH1 S21
LOG
6 dB / REF 0 dB
1: - 0.40100dB
800 MHz
0 dB
12
2: - 2.2058 dB
900 MHz
2
5
2: - 0.50480 dB
900 MHz
3
-6 dB
-12 dB
-18 dB
-24 dB
-30 dB
-36 dB
-42 dB
-48 dB
3: - 14.205 dB
1.8 GHz
4: - 7.8864 dB
2.5 GHz
-6 dB
-12 dB
3: - 4.2120 dB
1.8 GHz
5
4
4
3
-18 dB
-24 dB
-30 dB
-36 dB
-42 dB
-48 dB
4: - 12.637 dB
2.5 GHz
1
MHz
START . 030 MHz
10
MHz
100
MHz
3
1
GHz GHz
STOP 3000. 000000 MHz
1
MHz
START . 030 MHz
10
MHz
100
MHz
3
1
GHz GHz
STOP 3000. 000000 MHz
ESD Clamping - I/O to Gnd
(8kV Contact per IEC 61000-4-2)
ESD Clamping - I/O to Gnd
(30kV Contact per IEC 61000-4-2)
Note: Data is taken with a 10x attenuator
©
2010 Semtech Corp.
4
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RClamp2574N
PROTECTION PRODUCTS
Device Connection Options for Protection of Four
High-Speed Data Lines
This device is designed to protect four high-speed data
lines (two line pairs). It has been optimized for use on
Ethernet interfaces where large magnitude lightning
and ESD surges are expected. The RClamp2574N is
constructed using Semtech’s proprietary EPD process
technology. The EPD process provides low stand-off
(turn-on) voltages with significant reductions while
maintaining good clamping characteristics and high
surge capability. They feature a true operating voltage
of 2.5 volts. Each I/O pin pair features a low
capacitance steering diode bridge that is designed to
route harmful surge current into the internal low
voltage TVS diode. Each data pair is rated to
withstand 1000 Watts of surge power (8/20us impulse
waveform). When placed on the PHY side of the
magnetics, it can be used to meet the requirements of
Telcordia GR-1089, K.20, K.21, and other high energy
surge standards.
The RClamp2574N is designed with a flow through pin
configuration for easy layout. In a GbE application, TX+
and TX- lines would enter at pins 1, 2, 4, and 5 and exit
at pins 10, 9, 7, and 6 respectively. The traces should
be unbroken and run under the device as shown. Pins
3 and 8 are electrically connected to the three center
ground tabs. In a typical Ethernet application, these
pins as well as the tabs should be left floating (i.e. not
connected to ground).
Tx1+ In
Tx1- In
GND
Tx2+ In
GND
Tx2- In
5
6
Pin Configuration
1
10
Tx1+ Out
Tx1- Out
GND
GND
GND
Tx2+ Out
Tx2- Out
Layout Example
©
2010 Semtech Corp.
5
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