SMS3.3

3.3 Volt TVS Array For ESD and Latch-Up Protection PROTECTION PRODUCTS Description The SMS series of TVS arrays are designed to protect sensitive electronics from damage or latch-up due to ESD, lightning, and other voltage-induced transient events. Each device will protect up to four lines operating at 3.3 volts. The SMS3.3 is a solid-state device designed specifically for transient suppression. It is constructed using Semtech’s proprietary EPD process technology. The EPD process provides low standoff voltages with significant reductions in leakage currents and capacitance over traditional pn junction processes. They offer desirable characteristics for board level protection including fast response time, low clamping voltage and no device degradation. The SMS3.3 may be used to meet the immunity requirements of IEC 61000-4-2, level 4 (±15kV air, ±8kV contact discharge). The low cost SOT23-6L package makes them ideal for use in portable electronics such as cell phones, PDA’s, and notebook computers. SMS3.3 Features Transient protection for 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) 12A (8/20µs) Protects four I/O lines Working voltage: 3.3V Low leakage current (25 >15 260 (10 seconds) -55 to +125 -55 to +150 Units Watts A kV o o o C C C Electrical Characteristics SMS3.3 Par ame te r Reverse Stand-Off Voltage Punch-Through Voltage Snap -Back Voltage Reverse Leakage Current Clamp ing Voltage Clamp ing Voltage Clamp ing Voltage Steering Diode Forward Voltage (Reverse Clamp ing Voltage) Junction Cap acitance Symbo l V RWM V PT V SB IR VC VC VC VF Cj IPT = 2µ A ISB = 50mA V RWM = 3.3V, T=25°C IPP = 1A , tp = 8/20µ s A ny I/O to Ground IPP = 5A , tp = 8/20µ s A ny I/O to Ground IPP = 12A , tp = 8/20µ s A ny I/O to Ground IPP = 1A , tp = 8/20µ s A ny I/O to Ground Each I/O p in and Ground V R = 0V, f = 1MHz 35 3.5 2.8 0.05 0.5 4.5 6.8 8.7 1.7 40 Co nditio ns Minimum Typical Maximum 3.3 Units V V V µA V V V V pF  2004 Semtech Corp. 2 www.semtech.com SMS3.3 PROTECTION PRODUCTS PRODUCTS Non-Repetitive Peak Pulse Power vs. Pulse Time 10 Peak Pulse Power - PPk (kW) Power Derating 110 100 90 % of Rated Power or I PP 80 70 60 50 40 30 20 10 1 0.1 0.01 0.1 1 10 Pulse Duration - tp (µs) 100 1000 0 0 25 50 75 100 125 150 Ambient Temperature - TA (oC) Pulse Waveform 110 100 90 80 70 60 50 40 30 20 10 0 0 5 10 15 Time (µs) 20 25 30 td = IPP/2 PP Clamping Voltage Peak Clamping Voltage vs. Peak Pulse Current 10 Clamping Voltage - V (V) C Waveform Parameters: tr = 8µs td = 20µs e-t 9 8 7 6 5 4 3 2 1 0 0 2 4 6 8 10 12 14 Peak Pulse Current - IPP (A) Percent of I Waveform Parameters: tr = 8µs td = 20µs For w ard Voltage vs. For w ard Current orward Voltage For ard orw 10 9 8 Forward Voltage- V (V) F Capacitance - Cj (pF) 7 6 5 4 3 2 1 0 0 2 4 6 8 10 12 14 Forward Current - IF (A) 30 40 Re erse Voltage Capacitance vs. Rever se Voltage I/O to GND f = 1MHz 20 Waveform Parameters: tr = 8µs td = 20µs 10 0 0 1 2 Reverse Voltage - VR (V) 3 4  2004 Semtech Corp. 3 www.semtech.com SMS3.3 PROTECTION PRODUCTS Applications Information Device Connection for Protection of Four Data Lines The SMS3.3 is designed to protect up to four unidirectional data lines. The device is connected as follows: 1. Unidirectional protection of four I/O lines is achieved by connecting pins 1, 3, 4 and 6 to the data lines. Pin 2 and 5 are connected to ground. The ground connections should be made directly to the ground plane for best results. The path length is kept as short as possible to reduce the effects of parasitic inductance in the board traces. 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: Place the TVS near the input terminals or connectors to restrict transient coupling. Minimize the path length between the TVS and the protected line. Minimize all conductive loops including power and ground loops. The ESD transient return path to ground should be kept as short as possible. Never run critical signals near board edges. 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 compared 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. Protection of Four Unidirectional Lines SMS3.3 Circuit Diagram  2004 Semtech Corp. 4 www.semtech.com SMS3.3 PROTECTION PRODUCTS PRODUCTS Typical Applications  2004 Semtech Corp. 5 www.semtech.com SMS3.3 PROTECTION PRODUCTS Outline Drawing - SO-8 Outline Drawing -SOT23 6L A e1 N EI 1 ccc C 2X N/2 TIPS B 2 E D H GAGE PLANE 0.25 e DETAIL D aaa C A2 SEATING PLANE C A1 bxN bbb C A-B D A SEE DETAIL SIDE VIEW L (L1) H c DIM A A1 A2 b c D E1 E e e1 L L1 N 01 aaa bbb ccc DIMENSIONS INCHES MILLIMETERS MIN NOM MAX MIN NOM MAX .057 .035 .000 .006 .035 .045 .051 .010 .020 .003 .009 .110 .114 .118 .060 .063 .069 .110 BSC .037 BSC .075 BSC .012 .018 .024 (.024) 6 0° 10° .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 3.00 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 01 A 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 Z C G P X Y Z DIMENSIONS MILLIMETERS INCHES (.098) .055 .037 .024 .043 .141 (2.50) 1.40 0.95 0.60 1.10 3.60 P NOTES: 1. THIS LAND PATTERN IS FOR REFERENCE PURPOSES ONLY. CONSULT YOUR MANUFACTURING GROUP TO ENSURE YOUR COMPANY'S MANUFACTURING GUIDELINES ARE MET.  2004 Semtech Corp. 6 www.semtech.com SMS3.3 PROTECTION PRODUCTS PRODUCTS Marking Ordering Information Part Number SMS3.3.TC SMS3.3.TCT Lead Finish SnPb Pb free Qty per Reel 3,000 3,000 R eel Size 7 Inch 7 Inch Note: (1) No suffix indicates tube pack. Top Side Mark Tape and Reel Specification Device Orientation in Tape: Direction of Feed Tape Specifications (per EIA 481) Reel Material: Tape Material: Tape Width: Component Pitch (max.): Component Cavity Play: Static Dissipative Static Dissipative 8mm +/- 0.30mm 4mm +/- 0.10mm 20° Contact Information Semtech Corporation Protection Products Division 200 Flynn Rd., Camarillo, CA 93012 Phone: (805)498-2111 FAX (805)498-3804  2004 Semtech Corp. 7 www.semtech.com