PROTECTION PRODUCTS - RailClamp® Description
A RailClamp® is a low capacitance TVS array designed to protect high speed data interfaces. This series has been specifically designed to protect sensitive components which are connected to data and transmission lines from overvoltage caused by electrostatic discharge (ESD), electrical fast transients (EFT), and lightning. The unique design incorporates eight surge rated, low capacitance steering diodes and a TVS diode in a single package. During transient conditions, the steering diodes direct the transient to either the positive side of the power supply line or to ground. The internal TVS diode prevents over-voltage on the power line, protecting any downstream components. The RClamp®0554S is in a 6-lead SOT-23 package. The leads are finished with lead-free matte tin. Each device will protect up to four high-speed lines. They may be used to meet the ESD immunity requirements of IEC 61000-4-2, Level 4 (15kV air, 8kV contact discharge). The combination of small size, low capacitance, and high surge capability makes them ideal for use in applications such as 10/100 Ethernet, USB 2.0, and video interfaces.
RailClamp® Low Capacitance TVS Diode Array
Features
ESD protection for high-speed data lines to IEC 61000-4-2 (ESD) ±15kV (air), ±8kV (contact) IEC 61000-4-4 (EFT) 40A (5/50ns) IEC 61000-4-5 (Lightning) 25A (8/20μs) Array of surge rated diodes with internal TVS Diode Small package saves board space Protects four I/O lines and Voltage Bus Low capacitance: 5pF (VR=0V) Low clamping voltage Low operating voltage: 5.0V Solid-state silicon-avalanche technology
RClamp0554S
Mechanical Characteristics
JEDEC SOT-23 6L package Pb-Free, Halogen Free, RoHS/WEEE Compliant Molding compound flammability rating: UL 94V-0 Marking : Marking code + date code Packaging : Tape and Reel
Applications
USB 2.0 Power and Data Line Protection Video Graphics Cards Monitors and Flat Panel Displays Digital Video Interface (DVI) Notebook Computers IEEE 1394 Firewire Ports
Circuit Diagram
Schematic and PIN Configuration
5
1
3
4
6
2
SOT-23 6L (Top View)
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RClamp0554S
PROTECTION PRODUCTS Absolute Maximum Rating
R ating Peak Pulse Power (tp = 8/20μs) Peak Pulse Current (tp = 8/20μs) ESD per IEC 61000-4-2 (Air) ESD per IEC 61000-4-2 (Contact) Operating Temperature Storage Temperature Symbol Pp k IP P VESD TJ TSTG Value 375 25 +/- 30 +/- 25 -55 to +125 -55 to +150 Units Watts A kV °C °C
Electrical Characteristics (T=25oC)
Parameter Reverse Stand-Off Voltage Reverse Breakdown Voltage Reverse Leakage Current Clamping Voltage Clamping Voltage Clamping Voltage Junction Capacitance Symbol VRWM V BR IR VC VC VC Cj It = 1mA VRWM = 5V, T=25°C IPP = 1A, tp = 8/20μs Any I/O to GN D IPP = 10A, tp = 8/20μs Any I/O to GN D IPP = 25A, tp = 8/20μs Any I/O to GN D Any I/O to GN D VR = 0V, f = 1MHz I/O to I/O VR = 0V, f = 1MHz 3 6 0.5 9.8 12 15 5 Conditions Minimum Typical Maximum 5 Units V V μA V V V pF pF
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RClamp0554S
PROTECTION PRODUCTS Typical Characteristics
Non-Repetitive Peak Pulse Power vs. Pulse Time
10
110 100
Power Derating Curve
Peak Pulse Power - P PP (kW)
% of Rated Power or PP I
90 80 70 60 50 40 30 20 10 0
1
0.1 0.1 1 10 100 Pulse Duration - tp ( s)
0
25
50
75
100
125
150
Ambient Temperature - TA (oC)
Pulse Waveform
110 100 90 80 Percent of IPP 70 60 50 40 30 20 10 0 0 5 10 15 Time (µs) 20 25 30 td = IPP/2 e
-t
Clamping Voltage vs. Peak Pulse Current
Waveform Parameters: tr = 8µs td = 20µs
14 Clamping Voltage -VC (V) 12 10 8 6 4 2 0 0 5 10 15 20 25 30 Waveform Parameters: tr = 8µs td = 20µs
Peak Pulse Current - IPP (A)
Forward Voltage vs. Forward Current
Normalized Capacitance vs. Reverse Voltage
10 9 Forward Voltage - Vf (V) 8 7 6 5 4 3 2 1 0 0 5 10 15 20 25 30 Waveform Parameters: tr = 8µs td = 20µs
Cj(V R) / Cj(VR=0V)
1.2
1
0.8
0.6
0.4
0.2
f = 1 MHz
0 0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5
Peak Pulse Current - Ipp (A)
Reverse Voltage (VR) - V
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RClamp0554S
PROTECTION PRODUCTS Applications Information
Insertion Loss S21 - Any I/O to GND
CH1 S21 LOG 6 dB / REF 0 dB 1: -1.0964 dB 800 MHz 0 dB
12
Insertion Loss S21 - I/O to I/O
CH1 S21 LOG 6 dB / REF 0 dB 1: -0.47220 dB 800 MHz 0 dB
12
2: -1.2545 dB 900 MHz 3: -6.7229 dB 1.8 GHz 4: -16.4457 dB 2.5 GHz
2: -0.5278 dB 900 MHz
3 5
-6 dB
3
-6 dB -12 dB -18 dB -24 dB -30 dB -36 dB -42 dB -48 dB
3: -2.6811 dB 1.8 GHz 4: -9.2328 dB 2.5 GHz
-12 dB
5
4
-18 dB -24 dB -30 dB -36 dB -42 dB -48 dB
4
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 - Between any I/O and GND (+8kV Contact per IEC 61000-4-2)
ESD Clamping - Between any I/O and GND (-8kV Contact per IEC 61000-4-2)
Note: Data is taken with a 10x attenuator
Note: Data is taken with a 10x attenuator
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RClamp0554S
PROTECTION PRODUCTS Applications Information
Device Connection Options for Protection of Four High-Speed Data Lines The RClamp0554S is designed to protect four data lines from transient over-voltages by clamping them to a fixed reference. When the voltage on the protected line exceeds the reference voltage (plus diode VF) the steering diodes are forward biased, conducting the transient current away from the sensitive circuitry. Data lines are connected at pins 1, 3, 4 and 6. The negative reference (REF1) is connected at pin 2. This pin should be connected directly to a ground plane on the board for best results. The path length is kept as short as possible to minimize parasitic inductance. The positive reference (REF2) is connected at pin 5. The options for connecting the positive reference are as follows: 1. To protect data lines and the power line, connect pin 5 directly to the positive supply rail (VCC). In this configuration the data lines are referenced to the supply voltage. The internal TVS diode prevents over-voltage on the supply rail. 2. The RClamp0554S can be isolated from the power supply by adding a series resistor between pin 5 and VCC. A value of 100kΩ is recommended. The internal TVS and steering diodes remain biased, providing the advantage of lower capacitance. 3. In applications where no positive supply reference is available, or complete supply isolation is desired, the internal TVS may be used as the reference. In this case, pin 5 is not connected. The steering diodes will begin to conduct when the voltage on the protected line exceeds the working voltage of the TVS (plus one diode drop). ESD Protection With RailClamps® RailClamps are optimized for ESD protection using the rail-to-rail topology. Along with good board layout, these devices virtually eliminate the disadvantages of using discrete components to implement this topology. Consider the situation shown in Figure 1 where discrete diodes or diode arrays are configured for rail-torail protection on a high speed line. During positive duration ESD events, the top diode will be forward biased when the voltage on the protected line exceeds Data Line and Power Supply Protection Using Vcc as reference
Data Line Protection with Bias and Power Supply Isolation Resistor
Data Line Protection Using Internal TVS Diode as Reference
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RClamp0554S
PROTECTION PRODUCTS Applications Information (continued)
the reference voltage plus the VF drop of the diode. For negative events, the bottom diode will be biased when the voltage exceeds the VF of the diode. At first approximation, the clamping voltage due to the characteristics of the protection diodes is given by: VC = VCC + VF VC = -VF
PIN Descriptions
(for positive duration pulses) (for negative duration pulses)
However, for fast rise time transient events, the effects of parasitic inductance must also be considered as shown in Figure 2. Therefore, the actual clamping voltage seen by the protected circuit will be: VC = VCC + VF + LP diESD/dt (for positive duration pulses) VC = -VF - LG diESD/dt (for negative duration pulses) ESD current reaches a peak amplitude of 30A in 1ns for a level 4 ESD contact discharge per IEC 61000-4-2. Therefore, the voltage overshoot due to 1nH of series inductance is: V = LP diESD/dt = 1X10-9 (30 / 1X10-9) = 30V Example: Consider a VCC = 5V, a typical VF of 30V (at 30A) for the steering diode and a series trace inductance of 10nH. The clamping voltage seen by the protected IC for a positive 8kV (30A) ESD pulse will be: VC = 5V + 30V + (10nH X 30V/nH) = 335V This does not take into account that the ESD current is directed into the supply rail, potentially damaging any components that are attached to that rail. Also note that it is not uncommon for the VF of discrete diodes to exceed the damage threshold of the protected IC. This is due to the relatively small junction area of typical discrete components. It is also possible that the power dissipation capability of the discrete diode will be exceeded, thus destroying the device. The RailClamp is designed to overcome the inherent disadvantages of using discrete signal diodes for ESD suppression. The RailClamp’s integrated TVS diode
“Rail-T Pro Topology Figure 1 - “Rail-To-Rail” Pr o t ection Topology (First Approximation)
Figure 2 - The Effects of Parasitic Inductance When Using Discrete Components to Implement Rail-T Pro Rail- To-Rail Pr o t ection
Rail-T Pro Figure 3 - Rail- To-Rail Pr o t ection Using RailClamp Arrays RailClam p T V S Arra ys
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RClamp0554S
PROTECTION PRODUCTS Applications Information (continued)
helps to mitigate the effects of parasitic inductance in the power supply connection. During an ESD event, the current will be directed through the integrated TVS diode to ground. The maximum voltage seen by the protected IC due to this path will be the clamping voltage of the device. Universal Serial Bus ESD Protection The RClamp0554S may also be used to protect the USB ports on monitors, computers, peripherals or portable systems. Each device will protect up to two USB ports (Figure 4). When the voltage on the data lines exceed the bus voltage (plus one diode drop), the internal rectifiers are forward biased conducting the transient current away from the protected controller chip. The TVS diode directs the surge to ground. The TVS diode also acts to suppress ESD strikes directly on the voltage bus. Thus, both power and data pins are protected with a single device.
RClamp0554S
Figure 4 - Dual USB Port Protection
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RClamp0554S
PROTECTION PRODUCTS Outline Drawing - SO-8 Outline Drawing -SOT23 6L
A e1 N EI 1 ccc C 2X N/2 TIPS e B 2 E D
DIM
A A1 A2 b c D E1 E e e1 L L1 N 01 aaa bbb ccc
DIMENSIONS MILLIMETERS INCHES MIN NOM MAX MIN NOM MAX
.057 .035 .006 .000 .035 .045 .051 .020 .010 .009 .003 .110 .114 .122 .060 .063 .069 .110 BSC .037 BSC .075 BSC .012 .018 .024 (.024) 6 10° 0° .004 .008 .008 1.45 0.90 0.00 0.15 .90 1.15 1.30 0.25 0.50 0.08 0.22 2.80 2.90 3.10 1.50 1.60 1.75 2.80 BSC 0.95 BSC 1.90 BSC 0.30 0.45 0.60 (0.60) 6 0° 10° 0.10 0.20 0.20
2X E/2
D aaa C A2 SEATING PLANE C A1 bxN bbb C A-B D A
H GAGE PLANE 0.25 L (L1) SEE DETAIL SIDE VIEW c
01
A
DETAIL
A
NOTES: 1. CONTROLLING DIMENSIONS ARE IN MILLIMETERS (ANGLES IN DEGREES).
2. DATUMS -A- AND -B- TO BE DETERMINED AT DATUM PLANE -H3. DIMENSIONS "E1" AND "D" DO NOT INCLUDE MOLD FLASH, PROTRUSIONS OR GATE BURRS.
Land Pattern -SOT23 6L
X
DIM
(C) G Y P Z C G P X Y Z
DIMENSIONS INCHES MILLIMETERS
(.098) .055 .037 .024 .043 .141 (2.50) 1.40 0.95 0.60 1.10 3.60
NOTES: 1. THIS LAND PATTERN IS FOR REFERENCE PURPOSES ONLY. CONSULT YOUR MANUFACTURING GROUP TO ENSURE YOUR COMPANY'S MANUFACTURING GUIDELINES ARE MET.
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RClamp0554S
PROTECTION PRODUCTS Marking Codes Ordering Information
Part Number Lead Finish Matte Tin Qty per Reel 3,000 R eel Size 7 Inch
V54
YW = 2 - Alphanumeric characters for Date Code
Tape and Reel Specification
YW
RClamp 0554S.TCT
Pin 1 Location
User Direction of feed
A0 3.23 +/-0.05 mm
B0 3.17 +/-0.05 mm
K0 1.37 +/-0.05 mm
Tape Width
B, (Max)
D
D1
E
F
K (MAX)
P
P0
P2
T(MAX)
W 8.0 mm + 0.3 mm - 0.1 mm
8 mm
4.2 mm (.165)
1.5 + 0.1 mm - 0.0 mm
1.0 mm ±0.05
1.750±.10 mm
3.5±0.05 mm
2.4 mm
4.0±0.1 mm
4.0±0.1 mm
2.0±0.05 mm
0.4 mm
Contact Information
Semtech Corporation Protection Products Division 200 Flynn Road, Camarillo, CA 93012 Phone: (805)498-2111 FAX (805)498-3804
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