SM712.TCT

SM712 Asymmerical TVS Diode for Extended Common-Mode RS-485 PROTECTION PRODUCTS Description Features The SM712 transient voltage suppressor (TVS) diode is designed for asymmetrical (12V to -7V) protection in multi-point data transmission standard RS-485 applications. The SM712 may be used to protect devices from transient voltages resulting from electrostatic discharge (ESD), eletrical fast transients (EFT), and lightning. • Transient Protection to s IEC 61000-4-2 (ESD): ±30kV (Air), ±30kV (Contact) s IEC 61000-4-4 (EFT): 40A (5/50ns) s IEC 61000-4-5 (Lightning): 21A for 12V TVS & 38A for 7V TVS (tp = 8/20µs) • Protects two +12V to -7V lines • Peak pulse power (tp = 8/20μs): 500-700W • Low capacitance • Low clamping voltage • Solid-State Silicon-Avalanche Technology The SM712 features more than 500 Watts (tp = 8/20 μs) of power handling capability to accommodate the higher transient voltage levels which may be expected in extended commom mode applications. This provides higher equipment reliability and eliminates the “guess work“ required when using Zener diodes that are not rated to handle such transient conditions. Mechanical Characteristics • • • • • JEDEC SOT23 Package Molding Compound Flammability Rating: UL 94V-0 Pb-Free, Halogen Free, RoHS/WEEE compliant Marking: 712 Packaging: Tape and Reel The SM712 replaces four discrete components by integrating two 12V and two 7V TVS diodes in a single package. The integrated design aids in reducing voltage over-shoot associated with trace inductance. The low clamping voltage of SM712 minimizes the stress on the protected transceiver. Applications Circuit Diagram Schematic and Pin Configuration I/O 1 • RS-485 tranceivers with extended common mode range • Security systems • Automatic Teller Machines • HFC systems • Networks I/O 2 1 3 2 12V 12V 7V 7V SM712 GND 1 3 2 SOT23 (Top View) SM712 Final Datasheet 10/17/2017 www.semtech.com Rev 6.0 Page 1 Semtech Absolute Maximum Ratings Rating Symbol Value Units Peak Pulse Power (tp = 8/20µs) PPK 550- 700 W Peak Pulse Current (tp = 8/20µs), Pin 1 or 2 to Pin 3 Peak Pulse Current (tp = 8/20µs), Pin 3 to Pin 1 or 2 IPP ESD per IEC 61000-4-2 (Contact)(1) ESD per IEC 61000-4-2 (Air)(1) VESD 30 30 kV Lead Soldering Temperature TL 260 (10 sec.) O C Operating Temperature TJ -55 to +125 O C -55 to +150 O C 21 Storage Temperature TSTG A 38 Electrical Characteristics (T=25OC unless otherwise specified) Parameter Symbol Conditions Reverse Stand-Off Voltage Reverse Breakdown Voltage Reverse Leakage Current VRWM VBR IR Clamping Voltage VC Clamping Voltage VC CJ Typ. Max. Pin 1 or Pin 2 to 3 12 Pin 3 to Pin 1 or 2 7 Units V It = 1mA, Pin 1 or 2 to Pin 3 13.3 It = 1mA, Pin 3 and Pin 1 or 2 7.5 V VR = 12 V, Pin 1 or Pin 2 to 3 1 VR = 7 V, Pin 3 to Pin 1 or 2 20 IPP = 5A, Pin 1 or 2 to Pin 3, tp = 8/20µs 20 IPP = 5A, Pin 3 to Pin 1 or 2, tp = 8/20µs 10 IPP = 21A, Pin 1 or 2 to Pin 3, tp = 8/20µs 26 IPP = 38A, Pin 3 to Pin 1 or 2, tp = 8/20µs 19 Pin 1 or 2 to Pin 3 75 Pin 3 to Pin 1 or 2 75 VR = 0V Junction Capacitance Min. μA V V pF VR =12V Pin 1 or 2 to Pin 3 57 VR =7V Pin 3 to Pin 1 or 2 35 Notes: (1): ESD Gun return path to Ground Reference Plane (GRP) (2): Transmission Line Pulse Test (TLP) Settings: tp = 100ns, tr = 0.2ns, ITLP and V TLP averaging window: t1 = 70ns to t2 = 90ns. (3): Dynamic resistance calculated from ITLP = 4A to ITLP = 16A. SM712 Final Datasheet 10/17/2017 www.semtech.com Rev 6.0 Page 2 Semtech Typical Characteristics Non-Repetitive Peak Pulse Power vs. Pulse Time Power Derating Curve 120 100 % of Rated Power or IPP Peak Pulse Power - PPP (kW) 10 Pin 3 to Pin 1 or 2 1 Pin 1 or 2 to Pin 3 0.1 80 60 40 20 TA = 25OC 0.01 DR040514-25-125-150 0.1 1 10 Pulse Duration - tp (µs) 100 0 1000 0 25 Clamping Voltage vs. Peak Pulse Current (tp = 8/20µs) 50 75 100 Ambient Temperature - TA (OC) 125 150 Capacitance vs. Reverse Voltage 80 30 70 60 Pin 1 or 2 to Pin 3 20 Capacitance - CJ (pF) Clamping Voltage - VC (V) 25 15 Pin 3 to Pin 1 or 2 10 Pin 3 to Pin 1 or 2 50 Pin 1 or 2 to Pin 3 40 30 20 5 10 TA = 25OC. f = 1 MHz. SM712 8x20us 7V SM712_AR_CAPvV 0 0 0 5 10 15 20 25 Peak Pulse Current - IPP (A) 30 35 0 40 4 6 8 10 12 14 Reverse Voltage - VR (V) TLP IV Curve (Pin 1 or 2 to Pin 3) TLP IV Curve (Pin 3 to Pin 1 or 2) 5 35 TA = 25OC tP = 100ns, tR = 0.2ns tMEAS = 70-90ns 30 TA = 25OC tP = 100ns tR = 0.2ns tMEAS = 70-90ns 0 25 -5 20 TLP Current (A) TLP Current (A) 2 15 10 -10 -15 -20 5 -25 0 SM712_TLP_NEG SM712_TLP_POS -30 -5 0 5 10 15 20 25 -14 www.semtech.com Rev 6.0 -10 -8 -6 -4 -2 0 TLP Voltage (V) TLP Voltage (V) SM712 Final Datasheet 10/17/2017 -12 Page 3 Semtech Typical Characteristics ESD Clamping Voltage (+8kV Contact per IEC 61000-4-2) ESD Clamping Voltage (-8kV Contact per IEC 61000-4-2) 180 0 TA = 25OC. Waveform IEC61000-4-2 +8kV. Measured with and corrected for 50Ω, 40dB Attenuator. 50Ω Scope Input Impedance, ≥2GHz BW. ESD Gun Return connected to Ground Reference Plane. 140 -20 -40 Clamping Voltage - VC (V) Clamping Voltage - VC (V) 160 120 100 80 60 40 20 -60 -80 -100 -120 TA = 25OC. Waveform IEC61000-4-2 -8kV. Measured with and corrected for 50Ω, 40dB Attenuator. 50Ω Scope Input Impedance, ≥2GHz BW. ESD Gun Return connected to ESD Ground Plane. -140 -160 SM712_P8_ESD SM712_IEC_N8_ESD 0 -180 -10 10 30 50 70 90 Time (ns) SM712 Final Datasheet 10/17/2017 10 30 50 70 90 Time (ns) www.semtech.com Rev 6.0 -10 Page 4 Semtech Application Information RS-485 Common Mode Voltages Device Connection for Protection of Two RS-485 Data Lines EIA RS-485 specifies a ±7V ground difference between devices on the bus. This permits the bus voltage to range from +12V (5V + 7V) to -7V (0-7V). VCC1 5V VCC2 5V 4000 ft Twisted Pair A The SM712 is designed to protect two RS-485 data lines in extended common mode applications. The SM712 may be used to protect devices from transient voltages resulting from ESD, EFT, and lightning. The device is designed with asymmetrical operating voltages for optimum protection. The TVS diodes at pins 1 and 2 have a working voltage of 12 volts. These pins are connected to the differential data line pairs. The TVS diodes at pin 3 have a working voltage of 7 volts. Pin 3 is connected to ground. The internal TVS diodes of the SM712 will protect the transceiver input from positive transient votlage spikes greater than 12V and negative spikes greater than 7V. INPUT B A B GND -+ 12V to -7V Common mode voltage RS-485 Protection Circuit VCC 5V SS SS RT SM05 A series current limiting resistor may be added in applications requiring enhanced surge immunity. D Circuit Board Layout Recommendations Good circuit board layout is critical for the suppression of fast rise time transients such as ESD. The following guidelines are recommended: • • • • • • OUTPUT 100 100 12V 12V 7V 7V R SM712 Place the SM712 near the input terminals or connectors to restrict electromagnetic coupling. Minimize the path length between the SM712 and the protected line. This minimizes voltage overshoot due to parastic inductance of board traces. Use ground planes whenever possible. Long, single trace ground conductors should be avoided. The ground pin (Pin 3) should be connected directly to a ground plane on the circuit board for best results. Minimize all conductive loops including power and ground loops. Never run critical signals near board edges. SM712 Final Datasheet 10/17/2017 www.semtech.com Rev 6.0 Page 5 Semtech Outline Drawing - SOT-23 e1 3 DIMENSIONS MILLIMETERS MIN NOM MAX B DIM E1 1 A A1 A2 b c D E1 E e e1 L L1 N 0 aaa bbb E 2 bxN bbb e D C A B 1.20 0.89 0.01 0.10 0.88 1.10 0.30 0.51 0.08 0.18 2.80 2.90 3.04 1.20 1.30 1.40 2.10 2.64 1.90 BSC 0.95 BSC 0.40 0.50 0.60 (0.55) 3 0° 8° 0.10 0.20 A A2 aaa C A SEATING PLANE H A1 C GAUGE PLANE SEATING PLANE 0 c C L L1 0.25 SIDE VIEW DETAIL A SEE DETAIL A 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. Land Pattern - SOT-23 X DIMENSIONS DIM MILLIMETERS (C) Z G Y C G E1 E X Y Z (2.20) 0.80 0.95 1.90 1.00 1.40 3.60 E1 E NOTES: SM712 Final Datasheet 10/17/2017 1. CONTROLLING DIMENSIONS ARE IN MILLIMETERS (ANGLES IN DEGREES). 2. THIS LAND PATTERN IS FOR REFERENCE PURPOSES ONLY CONSULT YOUR MANUFACTURING GROUP TO ENSURE YOUR COMPANY'S MANUFACTURING GUIDELINES ARE MET. 3. REFERENCE IPC-SM-782A. www.semtech.com Rev 6.0 Page 6 Semtech Marking Code 3 712 1 2 Tape and Reel Specification 712 712 712 Pin 1 Location User Direction of feed Ordering Information Part Number Qty per Reel Reel Size Carrier Tape Pitch SM712.TCT 3,000 7 Inch Plastic 4mm MicroClamp and uClamp are registered trademarks of Semtech Corporation. SM712 Final Datasheet 10/17/2017 www.semtech.com Rev 6.0 Page 7 Semtech IMPORTANT NOTICE Information relating to this product and the application or design described herein is believed to be reliable, however such information is provided as a guide only and Semtech assumes no liability for any errors in this document, or for the application or design described herein. Semtech reserves the right to make changes to the product or this document at any time without notice. Buyers should obtain the latest relevant information before placing orders and should verify that such information is current and complete. Semtech warrants performance of its products to the specifications applicable at the time of sale, and all sales are made in accordance with Semtech’s standard terms and conditions of sale. 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Semtech reserves the right to make changes to, or discontinue any products described in this document without further notice. Semtech makes no warranty, representation or guarantee, express or implied, regarding the suitability of its products for any particular purpose. All rights reserved. © Semtech 2015 Contact Information Semtech Corporation 200 Flynn Road, Camarillo, CA 93012 Phone: (805) 498-2111, Fax: (805) 498-3804 www.semtech.com SM712 Final Datasheet 10/17/2017 Rev 6.0 Page 8 Semtech