SLVU2.8-4 EPD TVS Diode Array For ESD and Latch-Up Protection PRELIMINARY PROTECTION PRODUCTS Description Features The SLV series of transient voltage suppressors are designed to protect low voltage, state-of-the-art CMOS semiconductors from transients caused by electrostatic discharge (ESD), cable discharge events (CDE), lightning and other induced voltage surges. u 400 Watts peak pulse power (tp = 8/20µs) u Transient protection for high speed data lines to The devices are constructed using Semtechs proprietary EPD process technology. The EPD process provides low standoff voltages with significant reductions in leakage currents and capacitance over siliconavalanche diode processes. The SLVU2.8-4 features integrated low capacitance compensation diodes that reduce the maximum capacitance to <8pF per line. This, combined with low leakage current, means signal integrity is preserved in high-speed applications such as 10/100 Ethernet. u u u u u u IEC 61000-4-2 (ESD) 15kV (air), 8kV (contact) IEC 61000-4-4 (EFT) 40A (tp = 5/50ns) IEC 61000-4-5 (Lightning) 24A (tp = 8/20µs) Protects two line pairs (four lines) Comprehensive pin out for easy board layout Low capacitance Low leakage current Low operating and clamping voltages Solid-state EPD TVS process technology Mechanical Characteristics u u u u The SLVU2.8-4 is in an SO-8 package and may be used to protect two high-speed line pairs. The flow-thru design minimizes trace inductance and reduces voltage overshoot associated with ESD events. The low clamping voltage of the SLVU2.8-4 minimizes the stress on the protected IC. JEDEC SO-8 package Molding compound flammability rating: UL 94V-0 Marking : Part number, date code, logo Packaging : Tape and Reel per EIA 481 Applications u u u u u u u The SLV series TVS diodes will meet the surge requirements of IEC 61000-4-2, Level 4. Circuit Diagram 10/100 Ethernet WAN/LAN Equipment Switching Systems Desktops, Servers, & Notebooks Instrumentation Base Stations Analog Inputs Schematic & PIN Configuration SO-8 (Top View) Revision 9/2000 1 www.semtech.com SLVU2.8-4 PROTECTION PRODUCTS Absolute Maximum Rating R ating Symbo l Value Units Peak Pulse Pow er (tp = 8/20ms) Pp k 400 Watts Peak Pulse Current (tp = 8/20ms) I PP 24 A ESD p er IEC 61000-4-2 (Air) ESD p er IEC 61000-4-2 (Contact) V ESD 25 15 kV Lead Soldering Temp erature TL 260 (10 seconds) o Op erating Temp erature TJ -55 to +125 o TSTG -55 to +150 o Storage Temp erature C C C Electrical Characteristics SLVU2.8-4 Par ame te r Reverse Stand -Off Voltage Symbo l Co nd itio ns Minimum Typ ical VRWM Maximum Units 2.8 V Punch -Th rough Voltage V PT IPT = 2µ A 3.0 V Snap -Back Voltage VSB ISB = 50mA 2.8 V Reverse Leakage Current IR V RWM = 2.8V, T=25°C (Each Line) 1 µA Clamp ing Voltage VC IPP = 2A , tp = 8/20µ s (Each Line) 5.5 V Clamp ing Voltage VC IPP = 5A , tp = 8/20µ s (Each Line) 8.5 V Clamp ing Voltage VC IPP = 24A , tp = 8/20µ s (Each Line) 15 V Maximum Peak Pulse Current I PP tp = 8/20µ s 24 A Junction Cap acitance Cj V R = 0V, f = 1MHz (Each Line) 8 pF ã 2000 Semtech Corp. 2 5 www.semtech.com SLVU2.8-4 PRELIMINARY PROTECTION PRODUCTS Typical Characteristics Non-Repetitive Peak Pulse Power vs. Pulse Time Power Derating Curve 110 10 90 % of Rated Power or I PP Peak Pulse Power - PPP (kW) 100 1 0.1 80 70 60 50 40 30 20 10 0 0.01 0.1 1 10 100 0 1000 25 Pulse Waveform 75 100 125 150 Clamping Voltage vs. Peak Pulse Current 14 110 Waveform Parameters: tr = 8µs td = 20µs 90 80 70 e 60 12 Clamping Voltage - VC (V) 100 Percent of IPP 50 Ambient Temperature - TA (oC) Pulse Duration - tp (µ s) -t 50 40 td = IPP/2 30 20 10 8 6 4 Waveform Parameters: tr = 8µs td = 20µs 2 10 0 0 0 5 10 15 20 25 0 30 ã 2000 Semtech Corp. 5 10 15 20 25 Peak Pulse Current - IPP (A) Time (µs) 3 www.semtech.com SLVU2.8-4 PROTECTION PRODUCTS Applications Information SLVU2.8-4 Circuit Diagram Device Connection for Protection of Four Data Lines Electronic equipment is susceptible to transient disturbances 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 SLVU2.8-4 is designed to protect sensitive components from damage and latchup which may result from such transient events. The SLVU2.8-4 can be configured to protect two highspeed line pairs. The device is connected as follows: 1 . Protection of two high-speed line pairs: The SLVU2.8-4 is designed such that the data lines are routed through the device. The first line pair enters at pins 1 and 2 and exit at pins 8 and 7 respectively. The second line pair enters at pins 3 and 4 and exits at pins 6 and 5. The traces must be connected at the bottom of the device as shown. Low Capacitance Protection of Two Differential Line Pairs Circuit Board Layout Recommendations for Suppression of ESD. Good circuit board layout is critical for the suppression of ESD induced transients. The following guidelines are recommended: l Place the SLVU2.8-4 near the input terminals or connectors to restrict transient coupling. l Minimize the path length between the TVS and the protected line. l Minimize all conductive loops including power and ground loops. l The ESD transient return path to ground should be kept as short as possible. l Never run critical signals near board edges. l Use ground planes whenever possible. ã 2000 Semtech Corp. 4 Line 1 1 8 Line 1 Line 2 2 7 Line 2 Line 3 3 6 Line 3 Line 4 4 5 Line 4 www.semtech.com SLVU2.8-4 PRELIMINARY PROTECTION PRODUCTS Typical Applications 10/100 Ethernet Protection Circuit ã 2000 Semtech Corp. 5 www.semtech.com SLVU2.8-4 PROTECTION PRODUCTS Applications Information (continued) EPD TVS Characteristics ,PP The SLVU2.8-4 is constructed using Semtechs proprietary 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 SLVU2.8-4 can effectively operate at 2.8V while maintaining excellent electrical characteristics. ,6% ,37 9%55 ,5 95:0 96% 937 9& ,%55 The EPD TVS employs a complex nppn structure in contrast to the pn structure normally found in traditional silicon-avalanche TVS diodes. The EPD mechanism is achieved by engineering the center region of the device such that the reverse biased junction does not avalanche, but will punch-through to a conducting state. This structure results in a device with superior dc electrical parameters at low voltages while maintaining the capability to absorb high transient currents. EPD TVS VI Characteristic Curve 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 (VRWM). During a transient event, the device will begin to conduct as it is biased in the reverse direction. When the punchthrough voltage (VPT) 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). ã 2000 Semtech Corp. 6 www.semtech.com SLVU2.8-4 PRELIMINARY PROTECTION PRODUCTS Outline Drawing - SO-8 Land Pattern - SO-8 ã 2000 Semtech Corp. 7 www.semtech.com SLVU2.8-4 PROTECTION PRODUCTS Ordering Information Par t Numbe r Wo r king Vo ltage Qty p e r R e e l R e e l Size SLVU2.8-4.TB 2.8V 500 7 Inch SLVU2.8-4.TE 2.8V 2,500 13 Inch Note: (1) No suffix indicates tube pack. Contact Information Semtech Corporation Protection Products Division 652 Mitchell Rd., Newbury Park, CA 91320 Phone: (805)498-2111 FAX (805)498-3804 ã 2000 Semtech Corp. 8 www.semtech.com