SLVU2.8.TCT

PROTECTION PRODUCTS 1 www.semtech.com PROTECTION PRODUCTS SLVU2.8 Low Voltage EPD TVS Diode For ESD and Latch-Up Protection Description Features Circuit Diagram Schematic & PIN Configuration Revision 06/25/2008 The SLV series of transient voltage suppressors are designed to protect low voltage, state-of-the-art CMOS semiconductors from transients caused by electro- static discharge (ESD), cable discharge events (CDE), lightning and other induced voltage surges. The devices are constructed using Semtech’s propri- etary EPD process technology. The EPD process pro- vides low standoff voltages with significant reductions in leakage currents and capacitance over silicon- avalanche diode processes. The SLVU2.8 features an integrated low capacitance compensation diode that allows the device to be configured to protect one unidirectional line or, when paired with a second SLVU2.8, two high-speed line pairs. The low capaci- tance design of the SLVU2.8 means signal integrity is preserved in high-speed applications such as 10/100 Ethernet. The SLVU2.8 is in an SOT23 package and has a low 2.8 volt working voltage. It is specifically designed to protect low voltage components such as Ethernet transceivers, laser diodes, ASICs, and high-speed RAM. The low clamping voltage of the SLVU2.8 minimizes the stress on the protected IC. The SLV series TVS diodes will exceed the surge re- quirements of IEC 61000-4-2, Level 4. Applications Mechanical Characteristics ‹ 10/100 Ethernet ‹ WAN/LAN Equipment ‹ Switching Systems ‹ Desktops, Servers, Notebooks & Handhelds ‹ Laser Diode Protection ‹ Base Stations ‹ 400 Watts peak pulse power (t p = 8/20μs) ‹ Transient 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) 24A (8/20μs) ‹ One device protects one unidirectional line ‹ Two devices protect two high-speed line pairs ‹ Low capacitance ‹ Low leakage current ‹ Low operating and clamping voltages ‹ Solid-state EPD TVS process technology ‹ JEDEC SOT23 package ‹ Molding compound flammability rating: UL 94V-0 ‹ Marking : U2.8 ‹ Packaging : Tape and Reel per EIA 481 SOT23 (Top View) 3 1 2 3 1 2 2© 2008 Semtech Corp. www.semtech.com PROTECTION PRODUCTSPROTECTION PRODUCTS SLVU2.8 Absolute Maximum Rating Electrical Characteristics gnitaR lobmyS eulaV stinU 02/8=pt(rewoPesluPkaeP μ )s P kp 004 sttaW 02/8=pt(tnerruCesluPkaeP μ )s I PP 42 A erutarepmeTgniredloSdaeL TL )sdnoces01(062 oC erutarepmeTgnitarepO TJ 521+ot55- oC erutarepmeTegarotS T GTS 051+ot55- oC 8.2UVLS retemaraP lobmyS snoitidnoC muminiM lacipyT mumixaM stinU egatloVffO-dnatSesreveR V MWR 1ot2niPro1ot3niP 8.2 V egatloVhguorhT-hcnuP V TP I TP 1ot3niP,Aμ2= 0.3 V egatloVkcaB-panS V BS I BS 1ot3niP,Am05= 8.2 V tnerruCegakaeLesreveR IR V MWR C°52=T,V8.2= 1ot2niPro1ot3niP 1 Aμ egatloVgnipmalC VC I PP t,A2= p sμ02/8= 1ot3niP 9.3 V egatloVgnipmalC VC I PP t,A5= p sμ02/8= 1ot3niP 7 V egatloVgnipmalC VC I PP t,A42= p sμ02/8= 1ot3niP 5.21 V egatloVgnipmalC VC I PP t,A5= p sμ02/8= 1ot2niP 5.8 V egatloVgnipmalC VC I PP t,A42= p sμ02/8= 1ot2niP 51 V ecnaticapaCnoitcnuJ Cj 2dna1ot3niP deit2dna1niP( )rehtegot VR zHM1=f,V0= 07 001 Fp ecnaticapaCnoitcnuJ Cj ).C.N3nip(1ot2niP VR zHM1=f,V0= 5 01 Fp scitsiretcarahCedoiDgnireetS egatloVnwodkaerBesreveR V RB IT 2ot3niP,Aμ01= 04 V tnerruCegakaeLesreveR I DR V MWR C°52=T,V8.2= 2ot3niP 1 Aμ egatloVdrawroF VF IF 3ot2niP,A1= 2 V 3© 2008 Semtech Corp. www.semtech.com PROTECTION PRODUCTSPROTECTION PRODUCTS SLVU2.8 Typical Characteristics Non-Repetitive Peak Pulse Power vs. Pulse Time 0 10 20 30 40 50 60 70 80 90 100 110 0 25 50 75 100 125 150 Ambient Temperature - TA ( oC) % o f R at ed P ow er o r I PP Power Derating Curve Pulse Waveform Clamping Voltage vs. Peak Pulse Current 0 10 20 30 40 50 60 70 80 90 100 110 0 5 10 15 20 25 30 T im e (µs) Pe rc en t o f I PP e-t td = IPP/2 W aveform Parameters: tr = 8µs td = 20µs 0.01 0.1 1 10 0.1 1 10 100 1000 Pulse Duration - tp (µs) Pe ak P ul se P ow er - P p k ( kW ) 0 2 4 6 8 10 12 14 16 18 0 5 10 15 20 25 30 35 Peak Pulse Current - IPP (A) C la m pi ng V ol ta ge - V C (V ) Pin 3 to 1 Waveform Parameters: tr = 8µs td = 20µs Forward Voltage vs. Forward Current 0 2 4 6 8 10 12 14 16 0 5 10 15 20 25 30 35 Forward Current - IF (A) Fo rw ar d Vo lta ge - V F (V ) Waveform Parameters: tr = 8µs td = 20µs Normalized Capacitance vs. Reverse Voltage 0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 1.8 2 0 0.5 1 1.5 2 2.5 3 Reverse Voltage - VR (V) C J( V R ) / C J(V R =0 ) Pin 2 to Pin 1 Pin 3 to Pin 1 and 2 f = 1MHz 4© 2008 Semtech Corp. www.semtech.com PROTECTION PRODUCTSPROTECTION PRODUCTS SLVU2.8 Typical Characteristics (Continued) Insertion Loss S21 START . 030 MHz 3 STOP 000 . 000 000 MHz CH1 S21 LOG 10 dB / REF 0 dB 5© 2008 Semtech Corp. www.semtech.com PROTECTION PRODUCTSPROTECTION PRODUCTS SLVU2.8 SLVU2.8 Circuit Diagram Protection of one unidirectional line Device Connection Options Electronic equipment is susceptible to transient distur- bances from a variety of sources including: ESD to an open connector or interface, direct or nearby lightning strikes to cables and wires, and charged cables “hot plugged” into I/O ports. The SLVU2.8 is designed to protect sensitive components from damage and latch- up which may result from such transient events. The SLVU2.8 can be configured to protect either one unidirectional line or two (one line pair) high-speed data lines. The options for connecting the devices are as follows: 1. Protection of one unidirectional I/O line: Protec- tion of one data line is achieved by connecting pin 3 to the protected line, and pins 1 and 2 to ground. This connection option will allow the device to operate on lines with positive polarity signal transi- tions (during normal operation). In this configura- tion, the device adds a maximum loading capaci- tance of 100pF. During positive duration tran- sients, the internal TVS diode will be reversed biased and will act in the avalanche mode, con- ducting the transient current from pin 3 to 1. The transient will be clamped at or below the rated clamping voltage of the device. For negative duration transients, the internal steering diode is forward biased, conducting the transient current from pin 2 to 3. The transient is clamped below the rated forward voltage drop of the diode. 2. Low capacitance protection of one differential line pair: Protection of a high-speed differential line pair is achieved by connecting two devices in anti- parallel. Pin 1 of the first device is connected to line 1 and pin 2 is connected to line 2. Pin 2 of the second device is connected to line 1 and pin 1 is connected to line 2 as shown. Pin 3 must be left open on both devices. During negative duration transients, the first device will conduct from pin 2 to 1. The steering diode conducts in the forward direction while the TVS will avalanche and conduct in the reverse direction. During positive transients, the second device will conduct in the same man- ner. In this configuration, the total loading capaci- tance is the sum of the capacitance (between pins 1 and 2) of each device (typically <10pF) making this configuration suitable for high-speed interfaces such as 10/100 Ethernet (See application note SI98-02). 1 2 3 Low capacitance protection of one high-speed line pair EPD TVS Characteristics The SLVU2.8 is constructed using Semtech’s propri- etary EPD technology. The structure of the EPD TVS is vastly different from the traditional pn-junction devices. At voltages below 5V, high leakage current and junction capacitance render conventional avalanche technology impractical for most applications. However, by utilizing the EPD technology, the SLVU2.8 can effectively operate at 2.8V while maintaining excellent electrical characteristics. The EPD TVS employs a complex nppn structure in contrast to the pn structure normally found in tradi- tional silicon-avalanche TVS diodes. The EPD mecha- nism is achieved by engineering the center region of the device such that the reverse biased junction does Applications Information 6© 2008 Semtech Corp. www.semtech.com PROTECTION PRODUCTSPROTECTION PRODUCTS SLVU2.8 Applications Information (continued) IPP ISB IPT IR VRWM VV PT VC VBRR IBRR SB EPD TVS IV Characteristic Curve Laser Diode Protection SLVU2.8 Circuit Board Layout Recommendations for Suppres- sion of ESD. Good circuit board layout is critical for the suppression of ESD induced transients. The following guidelines are recommended: z Place the SLVU2.8 near the input terminals or connectors to restrict transient coupling. z Minimize the path length between the TVS and the protected line. z Minimize all conductive loops including power and ground loops. z The ESD transient return path to ground should be kept as short as possible. z Never run critical signals near board edges. z Use ground planes whenever possible. 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. not avalanche, but will “punch-through” to a conduct- ing state. This structure results in a device with supe- rior dc electrical parameters at low voltages while maintaining the capability to absorb high transient currents. The IV characteristic curve of the EPD device is shown in Figure 1. The device represents a high impedance to the circuit up to the working voltage (V RWM ). During a transient event, the device will begin to conduct as it is biased in the reverse direction. When the punch- through voltage (V PT ) is exceeded, the device enters a low impedance state, diverting the transient current away from the protected circuit. When the device is conducting current, it will exhibit a slight “snap-back” or negative resistance characteristic due to its structure. This must be considered when connecting the device to a power supply rail. To return to a non-conducting state, the current through the device must fall below the snap-back current (approximately < 50mA). 7© 2008 Semtech Corp. www.semtech.com PROTECTION PRODUCTSPROTECTION PRODUCTS SLVU2.8 10/100 Ethernet Protection Circuit (Reference Semtech Application Note SI98-02 for more information) 10/100 Ethernet “Enhanced” Lightning Protection Circuit (Reference Semtech Application Note SI98-02 for more information) Typical Applications 8© 2008 Semtech Corp. www.semtech.com PROTECTION PRODUCTSPROTECTION PRODUCTS SLVU2.8 SLVU2.8 Spice Model sretemaraPecipS8.2UVLS retemaraP tinU )SVT(1D )DRCL(2D SI pmA 41-E90.6 9-E75.8 VB tloV 4.3 024 JV tloV 8.31 26.0 SR mhO 983.0 51.0 VBI pmA 3-E01 3-E01 OJC daraF 21-E57.42 21-E51.3 TT ces 9-E145.2 9-E145.2 M -- 541.0 311.0 N -- 1.1 1.1 GE Ve 11.1 11.1 0.6 nH Applications Information - SPICE Model 9© 2008 Semtech Corp. www.semtech.com PROTECTION PRODUCTSPROTECTION PRODUCTS SLVU2.8 Land Pattern - SOT23 Outline Drawing - SOT23 e e1 D E1 E bxN 1 2 3 A1 A2A 3X A bbb C A B B C SEATING PLANE aaa C 1.401.20 N 3 3 0 - 8°0°8°0° - .055.047 bbb .008 0.20 aaa .004 0.10 INCHES .114 L1 E D b e c .012 .003 .082 A1 DIM A MIN .000 .035 0.51 0.18 2.64 0.30 0.08 2.10 .022 - .075 - .093 .020 .007 .104 (0.55) 1.90 BSC - - 2.37 2.90 MILLIMETERS MAX 0.10 1.12 MIN DIMENSIONS 0.01 MAXNOM - - .004 .044 NOM 0.89 - - 3.042.80.110 .120 e1 .037 0.95 BSC L .015 .020 0.500.40.024 0.60 A2 .035 .037 0.950.88.040 1.02 E1 .051 1.30 SEE DETAIL A SIDE VIEW DATUMS AND TO BE DETERMINED AT DATUM PLANE-A- -B-2. CONTROLLING DIMENSIONS ARE IN MILLIMETERS (ANGLES IN DEGREES). NOTES: OR GATE BURRS. DIMENSIONS "E1" AND "D" DO NOT INCLUDE MOLD FLASH, PROTRUSIONS3. 1. -H- H DETAIL A 0.25C SEATING PLANE GAUGE PLANE 0 c L L1 REFERENCE IPC-SM-782A.2. E .037 0.95 Y Y GZ C E X E1 E1 .075 1.90 NOTES: 1. THIS LAND PATTERN IS FOR REFERENCE PURPOSES ONLY CONSULT YOUR MANUFACTURING GROUP TO ENSURE YOUR COMPANY'S MANUFACTURING GUIDELINES ARE MET. DIM Y Z G X C MILLIMETERSINCHES (2.20) .055 .141 .039 .031 (.087) 1.40 3.60 1.00 0.80 DIMENSIONS 10© 2008 Semtech Corp. www.semtech.com PROTECTION PRODUCTSPROTECTION PRODUCTS SLVU2.8 Contact Information Semtech Corporation Protection Products Division 200 Flynn Road, Camarillo, CA 93012 Phone: (805)498-2111 FAX (805)498-3804 Marking rebmuNtraP hsiniFdaeL leeRrepytQ eziSleeR CT.8.2UVLS bPnS 000,3 hcnI7 TCT.8.2UVLS eerfbP 000,3 hcnI7 U2.8 Ordering Information