EPT7008AG

Token Ring Transceiver Module ELECTRONICS INC. EPT7008AG • Optimized for Texas Instrument’s TMS38054 • • Supports both UTP and STP Transmission • • Overvoltage Protection Circuit • • Complies with or exceeds IEEE 802.5 Requirements • Electrical Parameters @ 25° C Impedance [Xmit/Rcv] Chip Side 600/150 Cable Side 150/100 1-16 MHz Xmit Rcv -1 -1 Insertion Loss (dB Max.) 32 MHz Xmit -7 36 MHz 1-6 MHz Rcv -18 Return Loss (dB Min.) 6-17 MHz Xmit Rcv -12 -15 17-25 MHz Xmit -10 Rcv -10 1-30 MHz Xmit -40 Rcv -40 Common Mode Rejection (dB Min.) 30-100 MHz Xmit Rcv -35 -30 100-200 MHz Xmit -10 Rcv -10 200-300 MHz Xmit -10 Rcv -10 -35 Crosstalk (dB Min.) 1-30 MHz Rcv Xmit -1 -25 Rcv Xmit -1 -18 Schematic PhPh+ Tx+ Vcc 2 13 14 12 11 .1µF 15 Ts+ Xmit Filter Impedance Matching Network 16 Ts- CMF 17 Tu18 Tu+ 19 Ch Gnd 23 Rs22 Rs+ Tx- 10 Gnd 2 9 Gnd 1 3 Rx+ 2 Vcc 1 1 CMF 21 Ru+ 20 Ru- Rx- 4 PhRet 24 Package A N Dim. Pin 1 I.D. PCA EPT7008AG Date Code P A B C D E F G H I J K L M N P Q Min. 1.290 .575 .300 1.110 .003 .100 .780 .015 .008 .090 0° .025 Dimensions (Inches) Max. Nom. 1.310 .585 .320 Typ. .020 Typ. .800 .021 .012 Typ. 8° .045 .030 .100 .092 .800 (millimeters) Min. Max. Nom. 32.77 14.60 7.62 28.19 0.076 2.54 19.81 .381 .203 .228 0° .635 33.27 14.86 8.13 Typ. .508 Typ. 20.32 .533 .305 Typ. 8° 1.14 .762 2.54 2.34 20.32 B Q D C F J H E M K L G I PCA ELECTRONICS, INC. 16799 SCHOENBORN ST. NORTH HILLS, CA 91343 CST7008Aa Rev. - 10/2/96 Product performance is limited to specified parameters. Data is subject to change without prior notice. TEL: (818) 892-0761 FAX: (818) 894-5791 http://www.pca.com Token Ring Transceiver Module ELECTRONICS INC. EPT7008AG The circuit below is a guideline for interconnecting PCA’s EPT7008AG with a typical Token Ring PHY chip for 4 Mb/16Mb applications over STP or UTP cable. Further details of system design should be obtained from the specific chip manufacturer. Note that this module is optimized for a “current source” driver such as TMS38054. Only one type of cable should be driven by the module: either UTP or STP. If you are using 120Ω cable or desire to install only one RJ45 connector thus leaving the STP use with a dongle when needed, please refer to PCA part numbers EPT7066 or similar parts optimized for 120Ω cable. Note that there is no need for the receiver side filtering. So consider this a cost effective solution for almost all Token Ring applications using this chip or similar chips. The pull down resistors to chassis via a cap shown around the RJ45 connector have been known to suppress unwanted radiation that unused wires pick up from the immediate environment. This is specially true if driving UTP cable. Their placement and use are to be considered carefully before design is finalized. No specific recommendation is made here for phantom circuitry, implementation varies. Please note that additional emission control has been observed if both nodes of the phantom bypass capacitor on the transmit channel are pulled to the chassis ground via suitable capacitors. It is recommended that there be a neat separation of ground planes in the layout. It is generally accepted practice to limit the plane off at least 0.05 inches away from the chip side pins of EPT7008AG. There need not be any ground plane beyond this point. For best results, PCB designer should design the outgoing traces preferably to be 75Ω/50Ω, (as the case may be) balanced and well coupled to achieve minimum radiation from these traces. Typical Application Circuit Connection to TMS38054 (or Equivalent) RCVINA 38 4 2 Vcc1 +5V +5V 100Ω 23 22 RCVINB 1(R) 6(G) DB-9 Connector 5(B) 9(O) Use only one connector 4 Rcv± 5 3 Xmit± 6 1 2 7 8 37 1 24 PHRET PHOUTA PHOUTB 50Ω/2W 19 29 27 10µF 10µF 13 50Ω/2W Chassis Ground 16 15 21 14 TMS38054 +5V 11 3 12 10 20 18 RJ45 DROUTB DROUTA 31 32 300Ω 300Ω EPT7008AG 17 +5V Notes : 1. Pin 24 is left unconnected. Applications vary. Your system may have a phantom drive return detection circuit needing pin 24 to be connected separately. 2. Red line connections to DB-9 Connector are 75Ω impedance traces. PCA ELECTRONICS, INC. 16799 SCHOENBORN ST. NORTH HILLS, CA 91343 CST7008Ab Rev. - 10/2/96 TEL: (818) 892-0761 FAX: (818) 894-5791 http://www.pca.com