TITE SM14LV1.7C TVSarray™ SCOTTSDALE DIVISION WWW . Microsemi .C OM T I T E Clamp™ T V S S E R I E S FEATURES • • • • • LAMP ULTRA LOW CLAMP FOR SENSITIVE I/O PORTS Clamps voltage to 1.7V max above signal level Operates over range from 3V through 30V Protects 10 lines uni and bi-directional to voltage bus UL 94V-O Flammability Classification APPLICATIONS • • • • SO-14 Package RS-232-B RS-422-A RS-423-A RS-485 MAXIMUM RATINGS • • • • • • • • Operating Temperature: -55°C to +50°C Storage Temperature: -55°C to +125°C Forward Surge Current: 8A (6/70µs) Minimum Reverse Breakdown Voltage ( VBR): 35V Working Peak Reverse Voltage VRWM to 30V Continuous forward current, IF: 400mA Power dissipation, (PD): 500mW Derating factor: 4.0 mW/°C Device Pin Out Configuration MECHANICAL PACKAGING • • • • • • • Tape & Reel per EIA Standard 481 2,500 pieces per 13 inch reel (STANDARD) Carrier tube 50 pcs (OPTIONAL) Molded SOIC 14 PIN Surface Mount Weight 2.5 grams (approximate) Marking: Logo, Date Code Pin 1 defined by dot ELECTRICAL CHARACTERISTICS PER LINE @ 25°C Unless otherwise specified PART NUMBER SM14LCV1.7C DEVICE MARKING LV1.7C VBR @100µA VRWM VOLTS VOLTS IR +50°c IR +25°c MIN MAX MAX 35 30 200* A @VR 30 CAP @ 3V CAP @10V A @VR pF pF MAX TYP TYP 500* 20 45 30 CAP @15V VF @ IF 100mA VF(surge) @ IPP = 8 A 6/70 µs pF VOLTS VOLTS TYP MAX MAX 27 0.5 1.70 * These values of leakage current IR represent multiple diodes as a result of their common anode or cathode connections. DIM A B C E F G H J K Copyright 2001 MSCXXXX.PDF 9-20-2004 REV J INCHES MIN MAX 0.336 0.344 0.150 0.158 0.228 0.244 0.011 0.021 0.004 0.010 0.053 0.069 0.006 0.010 0.189 0.206 0.016 0.050 MILLIMETERS MIN MAX 8.53 8.74 3.81 4.01 5.79 6.19 0.28 0.53 0.10 0.20 1.35 1.75 0.15 0.25 4.80 5.23 0.41 1.27 Microsemi Scottsdale Division 8700 E. Thomas Rd. PO Box 1390, Scottsdale, AZ 85252 USA, (480) 941-6300, Fax: (480) 947-1503 SM14LV1.7C OUTLINE TITE LAMP SM14LV1.7C TVSarray™ SCOTTSDALE DIVISION The SM14LV1.7C TITEClamp TVSarray is a 10 wire protector designed for clamping voltage spikes to lowest possible levels between the signal line and the Vcc supply or ground. This device incorporates Microsemi's proprietary "Self Programmable" feature that provides exceedingly tight clamping of only 1.7V maximum above signal line voltages ranging from 3.0V up through 30V. Destructive over-current is diverted through the plus and minus Vcc rails or ground for negative transients. One size fits all Downsizing of on chip components to sub-micron dimensions has improved performance, reduced component size and cost at the expense of lower failure voltage thresholds. The demand has surfaced for improved protection across data lines in highly automated manufacturing, monitoring and control systems. These environments are usually harsh and subject to conducted and induced transient voltages originating from sources including motors, solenoids and welders. WWW . Microsemi .C OM Application Notes For Using The SM14LV1.7C TITEClampTM TVSarrayTM The connection points are shown in figure 1. Pins 1 and 14 are connected to +Vcc, with pins 7 & 8 being either -Vcc or ground. The lines are spread out for purposes of illustrating the connections; however, the traces between signal lines and the TVS should be at an absolute minimum to reduce parasitic reluctance which causes overshoot per Faraday's laws of induction, V=L(di/dt). In figure 2, the segment for a single wire is detailed for improved illustration. A scaled illustration of clamping on a 12V signal line example is shown in figure 3. This depicts a small but acceptable rise in voltage above the signal during worse case transient conditions. + Vcc 2 4 1 Clamp Level To Signal Line 3 5 V 12 V Signal Voltage 1.7V Max + VCC 1 14 2 13 3 4 7 9 6 12 TITE LAMP - Vcc or Gnd t 11 5 10 6 9 7 8 - VCC or Gnd Single Line Detail Figure 2. Clamp Performance Figure 3. 8 10 Figure 1. Precautions in component placement and board layout: 1. Place the SM14LV1.7C directly at the board/signal line interface. 2. Keep all traces short for both signal lines and Vcc (and ground if applicable). 3. Eliminate ground loops. If the reader has further technical questions, please contact Microsemi-Scottsdale applications engineering at 480-941-6433 or 480-941-6524. Copyright 2001 MSCXXXX.PDF 9-20-2004 REV J Microsemi Scottsdale Division 8700 E. Thomas Rd. PO Box 1390, Scottsdale, AZ 85252 USA, (480) 941-6300, Fax: (480) 947-1503 SM14LV1.7C Line Installation