FT ROAMASEIORS Terminators Waar is A Tessonarorn? A terminator is a device which terminates the end of a signal line. Terminators can be internal to the system, or they can be in a separate configuration known as a TERMINATOR". This is the preferred configuration for expandable bus systems due to its versatility. Physically, terminators are connectors with a resistor network or a resistor and current-voltage regulation network encased in a protective overmold or shell assembly. Wry Use A Tesninarar? SCSI terminators have two basic functions; 1) establish the proper voltage and current for signal line operation; 2) match the line impedance and reduce reflection. 1. A terminator is an important working partner for a driver. When a driver pulls down the signal, a voltage low (true state) terminator supplies proper current to maintain the voltage level and when a driver pulls up the signal voltage high (negate), a terminator helps a driver make a quick and smocth negation. 2. Termination is needed at the two ends of the SCSI bus. The impedance mismatches are generally of greatest magnitude at the ends of the bus. A terminator matches a bus characteristic impedance and minimizes the reflection. GENERAL Types of TERMINATION There are two general methods of accomplishing termination: passive and active. Passive termination systems make use of fixed value resistors that place a matching resistance at the end of each signal line. This method is satisfactory for many applications. However, as signal speeds increase INTRODUCTION TO TERM and noise margins decrease, passive termination may no longer assure a reliable signal transmission. Active termination is the solution to this challenge. It reacts to an active negation driver and helps to make a clean monotonic wave shape in a high speed signal transfer by abilities of sourcing and sinking current and protecting a system by limiting maximum current. GENERAL COMFIQURATION OF TEAMINSTORS Terminators are available in two general configurations: feedthrough and end-of-line. A feedthrough termination typically installs between an equipment I/O port and a ribbon cable bus connector. This permits a quick and simplitied change in peripheral devices within an existing system configuration. This type of configuration is used if there is no INATORS provision for a pluggable terminator. Although these terminators generally appear as devices with an input and output port, they may also have no ports, in which case they are crimped directly to the cable. End-of-line terminators are installed at the end of a line, and do not continue the bus. The devise using this type of terminator must have both an input and output port. In addition, terminators may be of a shielded or unshielded construction. Shielded terminators are generally required when a bus in used between equipment cabinets. An unshielded terminator, conversely, is intended for use within an equipment cabinet. Thomas & Betis Electronics/OEM Division Tel: 901-682-7766 Fax: 901-680-5200 165 SPAMS OaES Ter minators FINE-PITCH D-SHIELDED TERMINATORS (FP SERIES) Gg w LRA92984 =: E60980 Byygican Paorgarigs INSULATION MATERIAL: Thermoplastic rated UL 94V.0. SHIELD: Steel Can. Contacts: High strength copper alloy; 30 inches minimum gold over 50 1 inches nickel in contact zone. ELECTRICAL PROPERTIES Wattace Ratina: 1/8 Watt MaxiMuM OPERATING VOLTAGE: 50 volts ENVIRONMENTAL PROSERTIES TEMPERATURE RATING: OG to 70C COONMPRSUBS TION? External, end-of-line, shielded APRUCATION: SCSI-2 & SCSI-3 systems. Shield allows use in equipment with separate enclosures. Recommescen anne CONNECTORS: HFROS50RA29JS1 HFROS50RA29J X14 HFROSORA29NS1 HFROSORA29NX1 TRMOSOEPDIFO : _TRMOSOFPANO - Differential ctive: Negation TERMPWR 220 OHM 330 OHM GND Single-Ended 1.846 [46.89] 1376 [34.95] | 1.653 [41.99] wo 261 /] 1.372 [34.85] 1.600/1.540 +4 [40.64]/[39.12] PIN CONTACT 50 PLACES ae ae Be ain hb 27m 206 75m 308 Sle Aap 7. *39 ane 077 LL ooocoo | mot 2.047 [52.00] oso i271 224 15.691 NOt - 100 [2.54] M2 i i 490 [12.45] MAX i pa 260 [6.60] Nae 50 GND LATCH [196] 1G Ne 12> Be hp Be 66 17H Em 19 241g 22m 73m Zoe 2. 3p 360 37a 3 OR 418 62 4, 656 Lhe 276 Gbe oe 5 TERK PWR Differential Active Negation Thomas & Betis Electronics/OEM Division Tel: 901-682-7766 Fax: 901-680-5200 170 Dimensions shown are for reference only. Dimensions are in millimeters (inches). FT ROAMASEIORS Terminators FINE-PITCH D-SHIELDED TERMINATORS (FP SERIES) G W BHyaical PRorEaTigs INSULATION MATERIAL: Thermoplastic rated UL 94-0. Contacts: High strength copper alloy: 30 jLinches minimum gold over 50 1 inches nickel in contact zone. ELECTHICAL Prorestigs WATTAGE Ratina: 1/8 Watt MaxiMuM OPERATING VOLTAGE: 50 volts ENVIRONMENTAL PROSEATIES TEMPERATURE RATING: OC to 70 COMPRES TIONS External, end-of-line, shielded APRUCATION: SCSI-2 and SCSI-3 systems. Shield allows use in equipment with separate enclosures. Aiecomvenpsn Manne ENONANED PORIS 2 HFRO68RA29BS1 HFRO68&RA29CSI HFRO68RA29BX1 HFRO68RA29CX1 _ 4500 [38,10] _ 1700 [43.18] 4.893 [48.08] U ooooc oo ae 8 A LU] 2-56 JACKSCREW TYP. PIN CONTACT 68 PLACES - 100 [2.54] - .224 [5.69] T. 050 [1.27] | . NO 34 | i 490 [12.45] MAX 1 i \-NO 35 no a8! I+ 1.822 [46.28] 4 MOG: : 0 TRMOS8EPANO |. -__ 2.280 [57.91] b+ 7. 616 [66.29] cn | i 1 i id 1 1 1 it Tie 184 2021 22 tiitiiidd itt 330 OHM k Tp F 150 OHM m1 TYP 330 OHM TYP EE SPEPPTS TP EPEE ETT TS PETTY TP PEEP PPT PEA 35 36 37 36 39 Differential AQ 41 42 43 64 45 46.47 28 49 5051 5259 5455 Se 57 90 59 00 61 62 63 64 65 66 67 08 CONTACT NUMBER ERSRSECSREREEREGTPRRER SEAS B ARE SRE 4 Active Negation Thomas & Betis Electronics/OEM Division Tel: 901-682-7766 Fax: 901-680-5200 174 Dimensions shown are for reference only. Dimensions are in millimeters (inches).