TransGuard ® TYPICAL CIRCUITS REQUIRING PROTECTION The following applications and schematic diagrams show where TransGuards® might be used to suppress various transient voltages: • ASIC Reset & Vcc Protection • Micro Controllers, Relays, DC Motors • I/O Port Protection • Keyboard Protection • Modem Protection • Sensor Protection • Preamplifier Protection • Audio Circuit Protection • LCD Protection • Optics Protection 76 TransGuard® AVX Multilayer Transient Voltage Protection Typical Circuits Requiring Protection ASIC RESET & Vcc PROTECTION IOCK S IOCS16 1 IRQSETO IRQSET1 1 μf 0.1 μf 0.01 μf 5.6V 0.1-0.4J 5.6V 0.1J DO-15 PDREF BCLK2 CLK14 IOR IOW LA20 CASH0 CASLO0 CASH1 CASL1 CASH2 CASL2 CASH3 CASL3 RAS0 RAS1 RAS2 RAS3 RAS4 Vcc RADO-7 AO-23 BHE NPBUSY CPUCLK GND DPH DRQIN NPERR HLDA ICHRDY RESET MASTER MNIO RDYIN PCUIN MICRO CONTROLLERS RELAYS, DC MOTORS TRANSGUARD® CHARACTERISTICS WORKING VOLTAGE ≥ RELAY OR MOTOR VOLTAGE ENERGY RATING TYPICALLY > 0.3J CAPACITANCE IS OF NO CONCERN CMOS RELAY DRIVER LM319 RELAY DRIVER VCC +5V +28V 30V 0.4J IN 1 IN 2 RELAY IN 1 1/2 MM74C908 MM74C918 1/2 LM319 IN 2 18V 0.4J RELAY = TransGuard® 77 TransGuard® AVX Multilayer Transient Voltage Protection Typical Circuits Requiring Protection I/O PORT PROTECTION TRANSGUARD® CHARACTERISTICS WORKING VOLTAGE TYPICALLY 14V - 18V ENERGY RATING TYPICALLY 0.05J - 0.1J CAPACITANCE SHOULD BE MINIMIZED SUB NOTEBOOK & PDA’S IOCS16 HDCS1 IDED7 HDCSO IDEENLO IDEENHI AVCC SETCUR AVSS RVI FILTER FGND250 FGND500 DO-D9 TC DACK IRQ3 IRQ4 PINTR FINTR IOR AEN FDRQ RESET PWRGD INDEX MTRO DRV1 DRVO MTR1 DIR STEP WDATA WG ATE TRKO WRPRT D T R 22 C T S 2 D T S D R X 2 NOTEBOOK & WORK STATION RXD2 DCD2 R12 DTR1 CTS1 RTS1 DSR1 TXD1 RXD1 DCD1 RI1 Vcc STROBE AUTOF ERROR INIT SLCTIN D D D D MAX 211 DRVR/RCVR R PARALLEL OUTPUT 0 TO 7 R R R D A T A H D S E L D AO S K C H G A9 ACK BUSY PE SLCT X2 X1/CLK PREN DRVTYP R R KEYBOARD PROTECTION TRANSGUARD® CHARACTERISTICS WORKING VOLTAGE >5.6V ENERGY RATING TYPICALLY <0.4J CAPACITANCE PREFERRED TO BE MINIMUM KEYBOARD CONTROLLER 74AHCT05 FERRITE BEAD DATA 14V - 18V 0.1J 74AHCT05 FERRITE BEAD CLOCK 14V - 18V 0.1J = TransGuard® 78 TransGuard® AVX Multilayer Transient Voltage Protection Typical Circuits Requiring Protection MODEM PROTECTION TRANSGUARD® CHARACTERISTICS WORKING VOLTAGE <26V ENERGY RATING ≥ 0.1J 330 pf 2/5/9 +5V Am7910 14 P1/8 10K ohm 1 0.68 μf 1489 P1/4 4 3 DTR 6 RTS 8 TD RC 0.68 μf TC 15 pf 24 P1/2 S1-5 10 MC0 7 23 MC1 2000 pf 22 pf MC2 P1/1 100 ohm MC3 MC4 1488 1 megohm 3 P1/3 2 RD 33 nf RES P1/6 4 6 CTS RING 5 9 CD 8 P1/5 10 14 1 7 2 4 BRTS 9/22 1.2K ohm 1.2K ohm +5V +5V +5V -5V 1 megohm +12V -12V SENSOR PROTECTION TRANSGUARD® CHARACTERISTICS WORKING VOLTAGE TYPICALLY >14V ENERGY RATING > 0.4J CAPACITANCE IS NO CONCERN 1 μf 120V MOV 180 ohm 1N4004 1N4004 1N4004 14V 0.4J 0.01 μf32 = TransGuard® 79 TransGuard® AVX Multilayer Transient Voltage Protection Typical Circuits Requiring Protection ANTENNA AND PREAMPLIFIER PROTECTION TRANSGUARD® CHARACTERISTICS WORKING VOLTAGE TYPICALLY 18V - 26V ENERGY RATING 0.05J - 0.9J CAPACITANCE OF CONCERN ON MANY DESIGNS PREAMPLIFIER PROTECTION +5V 10 μh 15 pf RF INPUT 1.8K ohm 0.01 μf MPF102 0.01 μf 26V 0.1J NEXT STAGE 180 pf 1 megohm 100 ohm AUDIO CIRCUIT PROTECTION TRANSGUARD® CHARACTERISTICS WORKING VOLTAGE TYPICALLY 14V - 18V ENERGY RATING 0.1J PAGER AUDIO PROTECTION NOTEBOOK, WORK STATION AUDIO PROTECTION Vcc IN 68 ohm INPUT FROM up OR DRIVER IC 68 ohm 2N2907 1K ohm 14V 0.1J IN 2N2222 14V 0.1J = TransGuard® 80 TransGuard® AVX Multilayer Transient Voltage Protection Typical Circuits Requiring Protection LCD PROTECTION TRANSGUARD® CHARACTERISTICS WORKING VOLTAGE < 5.6V ENERGY RATING < 0.1J LSI CONTROLLER 8 64 COM. DRIVER x1 D0-D7 WR RD LCD 240 x 64 240 3 CE 3 4 C/D SEG DRIVER x3 FS RESET 12 4.91 MHz 8 TRANSGUARD® OPTIONAL VC06LC18X500 StaticGuard S - RAM OPTICS PROTECTION TRANSGUARD® CHARACTERISTICS WORKING VOLTAGE ≤ 18V ENERGY RATING 0.1J CAPACITANCE SHOULD BE MINIMIZED OPTO ISOLATER PROTECTION LASER DIODE PROTECTION 5V 330 ohm 330 ohm 1N4148 1 ohm OUTPUT SIGNAL MICRO CONTROLLER 0.1 μf 100 ohm OPTO TRIAC 18V 0.1J 5.6V 0.1J TRIAC 2N4400 100 pf 2N6659 LASER DIODE 1N4148 3.9K ohm 330 ohm 2N2222 OUTPUT SIGNAL VN64GA 2N4400 1K ohm 2N6659 3.9K ohm = TransGuard® 81