SM712-N

SM712-N Transient Voltage Suppressors ROHS Features 400 watts peak pulse power (tp = 8/20μs) Protects two -7V to 12V lines Low capacitance Low clamping voltage Solid-state silicon avalanche technology IEC COMPATIBILITY (EN61000-4) IEC 61000-4-2 (ESD) ±15kV (air), ±8kV (contact) IEC 61000-4-4 (EFT) 40A (5/50ns) Mechanical Characteristics JEDEC SOT23 package Applications Protection of RS-485 transceivers with Molding compound flammability rating: UL extended common-mode range 94V-0 Security systems Marking : Making Code Automatic Teller Machines Packaging : Tape and Reel per EIA 481 HFC systems Net works Circuit Diagram Schematic & PIN Configuration I/O1 I/O2 1 2 1 12V 12V 3 7V 7V SM712 2 GND 3 SOT23(Top View) 1/5 SM712-N Transient Voltage Suppressors ROHS Absolute Maximum Rating Rating Symbol Value Units Peak Pulse Power ( tp =8/20μs) PPP 400 Watts Lead Soldering Temperature TL 260(10 sec.) °C Peak Pulse Current ( tp =8/20μs) Ipp Operating Temperature TJ -55 to + 125 °C TSTG -55 to +150 °C Storage Temperature 17/12 A Electrical Parameters (T=25 ℃) Symbol I Parameter IPP Maximum Reverse Peak Pulse Current VC Clamping Voltage @ IPP VRWM IR VBR IPP Working Peak Reverse Voltage VC VBR V RWM Maximum Reverse Leakage Current @ IT IR Breakdown Voltage @ IT IT Test Current IF Forward Current VF Forward Voltage @ IF IR IT V VRWM VBR VC IPP Electrical Characteristics SM712-N Parameter Pins 1 to 3 and 2 to 3 (12V TVS) Pins 3 to 1 and 3 to 2(7V TVS) Min Min Symbol Conditions V RWM Pin 3 to 1 or Pin 2 to 1 V BR I PT = 1mA Reverse Leakage Current IR V R = V RWM 1 20 μA Clamping Voltage VC I PP = 5A, tp = 8/20μs 20 12 V Clamping Voltage VC I PP = 17A, tp = 8/20μs 26 15 V VR = 0V, f = 1MHz 75 75 pF Junction Capacitance Cj Reverse Stand-Off Voltage Reverse Breakdown Voltage VR = V RWM , f = 1MHz Typ Max Typ 12 13.3 Max Units 7 V 7.5 45 V 45 pF 2/5 SM712-N Transient Voltage Suppressors ROHS Typical Characteristics Figure 1 Non-Repetitive Peak Pulse Power vs. Pulse Time Figure 2 Power Derating curve 110 100 % of R ated P owe r or I PP 400W 8/20µs Waveform 1 0.1 0.01 0.1 1 10 100 1000 90 80 70 60 50 40 30 20 10 0 25 0 50 Waveform Parameters: tr=8us td=20us 80 Clamping voltage – Vc (V) Percent of Ipp 110 100 90 e-t 60 50 td=IPP/2 40 30 20 10 0 0 5 10 100 125 150 175 Figure 4 Clamping Voltage vs. Peak Pulse Current Figure 3 PulseWaveform 70 75 Ambient Temperature - TA( ℃ ) Pulse Duration - tp (us) 20 15 25 30 Time(us) 24 22 20 18 16 14 12 10 8 6 4 2 0 Pin 1 to 3 and 2 to 3 Pin 3 to 1 and 3 to 2 Waveform Parameters: Tr=8us Td=20us 0 2 4 6 8 10 12 Peak Pulse Current - Ipp(A) Figure 5 Capacitance vs. Reverse Voltage 80 70 Capacitance - C J (pF) Peak Pulse Power - Ppp (KW) 10 60 50 40 30 20 10 f=1MHz 0 0 1 2 3 4 5 6 7 8 9 10 11 12 13 Reverse Voltage - VR (V) 3/5 14 16 SM712-N Transient Voltage Suppressors ROHS Application Information Device Connection for Protection of Two RS-485 DataLines 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). The SM712-N is designed to protect two RS-485 data lines in extended comm on mode applications. The SM712-N 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 internalTVS diodes of the SM712-N will protect the transceiver input from positive transient voltage spikes greater than 12V and Negative spikes greater than 7V. A series current limiting resistor may be added in applications requiring enhanced surge immunity. RS-485 Common Mode Voltages Vcc 1 5V Vcc 2 5V Twisted Pair B A 100 INPUT 100 B GND OUTPUT A 12V to -7V COMMON-MODE VOLTAGE RS-485 Protection Circuit Vcc 5V RT D 12V 7V 12V 7V R SM712-N 4/5 SM712-N Transient Voltage Suppressors ROHS Outline Drawing – SOT23 PACKAGE OUTLINE D SOT23 3 DIMENSIONS E1 E 0.25 θ 1 b L 2 A e A A2 b C e e1 INCHES MAX MIN MAX 0.900 1.150 0.035 0.045 A1 0.000 0.100 0.900 1.050 0.035 0.000 0.041 D 2.800 3.000 0.110 0.118 b 0.300 0.500 0.012 0.020 E 2.250 2.550 0.089 0.100 E1 1.200 1.400 0.047 0.055 0.950 BSC 0.004 0.037 BSC L 0.300 0.500 0.012 0.020 θ 0 8○ 0 8○ Notes DIMENSIONS M MILLIMETER MIN A2 e A1 Z SYMBOL DIM INCHES MILLIMETERS M 0.088 2.20 C 0.0058 0.15 Z 0.093 2.35 e 0.037 BSC 0.95 BSC e1 0.074 BSC 1.9 BSC b 0.0389 0.35 1. Dimensioning and tolerances per ANSI Y14.5M, 1985. 2. Controlling Dimension: Inches 3. Pin 3 is the cathode (Unidirectional Only). 4. Dimensions are exclusive of mold flash and metal burrs. Marking Codes Part Number SM712-N Marking Code 7AM Package Information Qty：3k/Reel 5/5