Token Ring Transceiver Module EPT7055A ELECTRONICS INC. • Optimized for voltage source driving into 150Ω • • Enhanced Common Mode performance over UTP • • Robust construction allows for solder reflow processes • • Complies with or exceeds IEEE 802.5 Requirements • Electrical Parameters @ 25° C Impedance (Ω) [Rcv] Insertion Loss (dB Min.) Chip Side 150 1-16 MHz Cable Side 32 MHz Return Loss (dB Min.) 36 MHz 1-6 MHz 44 MHz 6-17 MHz Xmit Rcv Xmit Rcv Xmit Rcv Xmit Rcv Xmit Rcv Xmit 100 -.6* -.5* -7 -1 -25 -30 -3 -3 -18 -23 -18 Common Mode Rejection (dB Min.) 17-24 MHz 1-30 MHz 30-100 MHz Crosstalk (dB Min.) 10 MHz 100-200 MHz Rcv Xmit Rcv Xmit Rcv Xmit Rcv Xmit Rcv -20 -10 -8 -57 -40 -35 -35 -20 -20 -50 * dB Max. Schematic 1 : .817 TX1+ 2 CT- 5 13 TXO- R2 3.9KΩ TX1- 4 R1 .1 µF LPF 150Ω 3.01KΩ 14 TXO+ 9 PHA 12 RX1+ .1 µF RX0+ 6 150Ω 11 RX1- RX0- 8 1 : .817 RXCT 7 10 PHB Dimensions Package A B Pin 1 I.D. PCA EPT7055A Date Code C H PCA ELECTRONICS, INC. 16799 SCHOENBORN ST. NORTH HILLS, CA 91343 E F D UTP G Dim. Min. A B C D E F G H I J 1.480 .255 .440 1.300 .010 .100 .130 .020 .010° .127 (Inches) Max. Nom. 1.500 .275 .460 Typ. .015 Typ. .150 .024 Typ. .137 (Millimeters) Min. Max. Nom. 37.60 6.48 11.43 33.02 .254 3.18 3.30 .508 .254 3.23 38.10 6.99 11.68 Typ. .381 Typ. 3.81 .610 Typ. 3.48 I J CST7055Aa Rev. D 6/2/97 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 EPT7055A ELECTRONICS INC. The circuit below is a guideline for interconnecting PCA’s EPT7055A with a typical Token Ring PHY chip for 4 Mb/16Mb applications over UTP cable. Further details of system design should be obtained from the specific chip manufacturer. Note that this module is optimized for a “voltage source” driver such as TI380C60. Typical insertion loss of the isolation transformer is 0.5dB up to 16 MHz. Under terminated conditions, to transmit a 2V pkpk signal across the cable, you must adjust the specific chip preset template control resistors to get at least 2.12V pk-pk across the transmit input pins. 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 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 a design is finalized. No specific recommendation is made here for phantom return 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 of EPT7055A. There need not be any ground plane beyond this point. For best results, PCB designer should design the outgoing traces preferably to be 50Ω, balanced and well coupled to achieve minimum radiation from these traces. RCVINA RCVINB 38 150Ω Typical Application Circuit Connection to TI380C60 (or Equivalent) 37 6 12 5 Xmit± 8 11 4 14 3 Rcv± 13 6 +5V +5V 1 50Ω/2W PHOUTA RJ45 2 7 8 9 29 50Ω/2W PHOUTB 27 10µF 10 10µF DROUTB 31 100Ω 32 100Ω DROUTA 422Ω TMS38060 2 4 EPT7055A 7 11 Common Mode 5 Notes : 1. Current limiting resistors R1 & R2 are included in this package. PCA ELECTRONICS, INC. 16799 SCHOENBORN ST. NORTH HILLS, CA 91343 CST7055Ab Rev. D 6/2/97 TEL: (818) 892-0761 FAX: (818) 894-5791 http://www.pca.com