SR70 RailClamp Low Capacitance TVS Diode Array  PROTECTION PRODUCTS - RailClamp Description Features RailClamps are surge rated diode arrays designed to (cid:139) Transient protection for high speed data lines to protect high speed data interfaces. The SR70 has IEC 61000-4-2 (ESD) ±15kV (air), ±8kV (contact) been specifically designed to protect sensitive compo- IEC 61000-4-4 (EFT) 40A (5/50ns) nents which are connected to data and transmission IEC 61000-4-5 (Lightning) 1kV, 24A (8/20µs) lines from over-voltages caused by electrostatic (cid:139) Array of surge rated, low capacitance diodes discharge (ESD), electrical fast transients (EFT), and (cid:139) Protects two I/O lines lightning. The SR70 has been optimized for use on (cid:139) Low capacitance (5pF typical) for high-speed ADSL and other high-speed interfaces. interfaces The unique design of the SR70 integrates four surge (cid:139) Low clamping voltage rated, low capacitance steering diodes in a low profile (cid:139) Solid-state silicon-avalanche technology SOT-143 package. It has a typical capacitance of only 5pF and may be used to protect two high-speed lines Mechanical Characteristics without sacrificing signal integrity. The SR70 is de- (cid:139) JEDEC SOT-143 package signed to replace “standard” rectifiers that are not (cid:139) UL 497B listed rated for the high energy surges that are normally (cid:139) Molding compound flammability rating: UL 94V-0 expected in telecommunications applications. (cid:139) Marking: R70 During transient conditions, the steering diodes direct (cid:139) Packaging: Tape and Reel per EIA 481 the transient to either the positive side of the power supply line or to ground. The maximum clamping Applications voltage seen by the protected circuit will be one diode drop (V ) above the supply (reference) voltage. The (cid:139) ADSL Lines F SR70 may be used as a stand alone device or in (cid:139) I2C Bus Protection conjunction with TVS diodes for enhanced protection. (cid:139) Video Line Protection (cid:139) T1/E1 secondary IC Side Protection (cid:139) Portable Electronics (cid:139) Microcontroller Input Protection (cid:139) WAN/LAN Equipment (cid:139) ISDN S/T Interface Circuit Diagram Schematic & PIN Configuration Pin 4 4 1 Pin 2 Pin 3 2 3 Pin 1 SOT-143 (Top View) Revision 03/03/06 1 www.semtech.com

SR70 PROTECTION PRODUCTS Absolute Maximum Rating Rating Symbol Value Units PeakPulseCurrent (t =8/20µs) I 24 A p PP RectifierRepetitivePeakReverseVoltage V 70 V RRM ESDperIEC61000-4-2(Air) V 15 kV ESD ESDperIEC61000-4-2(Contact) 8 Lead Soldering Temperature T 260(10sec.) °C L Operating Temperature T -55to+125 °C J StorageTemperature T -55to+150 °C STG Electrical Characteristics (T=25oC) SR70 Parameter Symbol Conditions Minimum Typical Maximum Units PeakReverseStand-Off Voltage V 70 V RRM ReverseBreakdown Voltage V I = 50µA 85 V BR t ReverseLeakageCurrent I V = 70V, T=25°C 5 µA R RWM Forward Clamping Voltage V I = 1A, t = 8/20µs 1.5 V FC PP p Forward Clamping Voltage V I = 10A, t = 8/20µs 3.3 V FC PP p Forward Clamping Voltage V I = 24A, t = 8/20µs 7 V FC PP p Junction Capacitance C Between I/O pinsand 5 10 pF j Ground V = 0V, f = 1MHz R Between I/O pins 3 pF V = 0V, f = 1MHz R  2006 Semtech Corp. 2 www.semtech.com

SR70 PROTECTION PRODUCTS Typical Characteristics Non-Repetitive Peak Pulse Power vs. Pulse Time Power Derating Curve 10 110 100 W) 90 wer - P (kPk 1 Power or IPP 678000 ak Pulse Po 0.1 % of Rated 345000 Pe 20 10 0.01 0 0.1 1 10 100 1000 0 25 50 75 100 125 150 Pulse Duration - tp (µs) Ambient Temperature - TA (oC) Pulse Waveform Capacitance vs. Reverse Voltage 110 0 100 Waveform I/O to GND Parameters: -2 f = 1MHz 90 tr = 8µs e 80 td = 20µs anc -4 nt of IPP 6700 e-t n Capacit --86 ce 50 e i Per 40 td = IPP/2 hang -10 30 % C -12 20 -14 10 0 -16 0 5 10 15 20 25 30 0 1 2 3 4 5 6 Time (µs) Reverse Voltage - VR (V) Forward Voltage vs. Forward Current 10 9 8 V) (F 7 V e - 6 g olta 5 V d 4 ar w 3 or Waveform F 2 Parameters: tr = 8µs 1 td = 20µs 0 0 5 10 15 20 25 30 35 40 45 50 Forward Current - IF (A)  2006 Semtech Corp. 3 www.semtech.com

SR70 PROTECTION PRODUCTS Applications Information SR70 Pin Configuration Device Connection Options for Protection of Two High-Speed Data Lines The SR70 is designed to protect two data lines from transient over-voltages by clamping them to a fixed reference. When the voltage on the protected line 4 1 exceeds the reference voltage (plus diode V ) the F steering diodes are forward biased, conducting the transient current away from the sensitive circuitry. Data lines are connected at pins 2 and 3. The nega- tive reference (REF1) is connected at pin 1. This pin should be connected directly to a ground plane on the board for best results. The path length is kept as short 2 3 as possible to minimize parasitic inductance. The positive reference (REF2) is connected at pin 4. The options for connecting the positive reference are as follows: 1. To protect data lines and the power line, connect Data Line and Power Supply Protection Using Vcc as pins 2 and 3 directly to the positive supply rail (V ). reference CC In this configuration the data lines are referenced to the supply voltage. An external TVS diode may be added between the supply rail and ground in order to prevent over-voltage on the supply rail. 2. In applications where no positive supply reference is available, or complete supply isolation is desired, an external TVS diode may be used as the refer- ence. 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). Matte Tin Lead Finish Matte tin has become the industry standard lead-free replacement for SnPb lead finishes. A matte tin finish is composed of 100% tin solder with large grains. Since the solder volume on the leads is small com- pared to the solder paste volume that is placed on the land pattern of the PCB, the reflow profile will be determined by the requirements of the solder paste. Therefore, these devices are compatible with both lead-free and SnPb assembly techniques. In addition, unlike other lead-free compositions, matte tin does not have any added alloys that can cause degradation of the solder joint.  2006 Semtech Corp. 4 www.semtech.com

SR70 PROTECTION PRODUCTS Outline Drawing - SOT-143 D A e H DIMENSIONS e/2 DIM INCHES MILLIMETERS MINNOMMAX MINNOMMAX 4 3 GAUGE 0 c A .031 - .048 0.80 - 1.22 B SEATING PLANE A1 .000 - .006 0.013 - 0.15 PLANE A2 .029 .035 .042 0.75 0.90 1.07 0.25 b .011 - .020 0.30 - 0.51 C b1 .029 - .037 0.76 - 0.94 L c .003 - .008 0.08 - 0.20 L1 D .110 .114 .120 2.80 2.90 3.04 E1 E DETAIL A E .082 .093 .104 2.10 2.37 2.64 E1 .047 .051 .055 1.20 1.30 1.40 e .075 1.92 BSC e1 .008 0.20 BSC L .015 .020 .024 0.40 0.50 0.60 L1 (.021) (0.54) 1 2 N0 0° 4- 8° 0° 4- 8° aaa .006 0.15 e1 bxN bbb .008 0.20 bbb C A B SIDE VIEW SEE DETAIL A ccc .004 0.10 A2 A 4X ccc C SEATING PLANE b1 A1 C aaa C A B NOTES: 1. CONTROLLING DIMENSIONS ARE IN MILLIMETERS (ANGLES IN DEGREES). 2. DATUMS - A - AND - B - TO BE DETERMINED AT DATUM PLANE-H- 3. DIMENSIONS "E1" AND "D" DO NOT INCLUDE MOLD FLASH, PROTRUSIONS OR GATE BURRS. 4. REFERENCE JEDEC STD TO-253, VARIATION D. Land Pattern - SOT-143 X1 X1 Y DIMENSIONS DIM INCHES MILLIMETERS C (.087) (2.20) Z E1 C G E1 .076 1.92 E2 E2 .068 1.72 G .031 0.80 X1 .039 1.00 X2 .047 1.20 Y .055 1.40 Y Z .141 3.60 X2 X1 NOTES: 1. THIS LAND PATTERN IS FOR REFERENCE PURPOSES ONLY CONSULT YOUR MANUFACTURING GROUP TO ENSURE YOUR COMPANY'S MANUFACTURING GUIDELINES ARE MET. 2. REFERENCE IPC-SM-782A.  2006 Semtech Corp. 5 www.semtech.com

SR70 PROTECTION PRODUCTS Marking Codes Marking Part Number Code SR70 R70 R70 SR70 Marking (Top View) Ordering Information Part Qtyper Lead Finish ReelSize Number Reel SR70.TC SnPb 3,000 7Inch SR70.TCT Pb Free 3,000 7Inch Lead-free version is RoHS/WEEE Compliant Contact Information Semtech Corporation Protection Products Division 200 Flynn Rd., Camarillo, CA 93012 Phone: (805)498-2111 FAX (805)498-3804  2006 Semtech Corp. 6 www.semtech.com