PCA EPT7076_99

Token Ring Transceiver Module
EPT7076
ELECTRONICS INC.
• Optimized for voltage source driving into 150 ohms •
• 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)
[Xmit/Rcv]
Insertion Loss
(dB)
Chip Side
150
1-16
MHz
Max.
32
MHz
Return Loss
(dB Min.)
36
MHz
1-6
MHz
44
MHz
6-17
MHz
Common Mode Rejection
(dB Min.)
17-25
MHz
1-30
MHz
30-100
MHz
100-200
MHz
Crosstalk
(dB Min.)
200-300
MHz
1-30
MHz
Min. Max. Min. Max. Min. Max.
Cable Side Xmit Rcv Xmit Rcv Xmit Rcv Xmit Rcv Xmit Rcv Xmit Rcv Xmit Rcv Xmit Rcv Xmit Rcv Xmit Rcv Xmit Rcv
100
-.8
-.6
-7
-1
-25
-3
-30
-3
-18
-23
-12
-20
-8
-10
-50
-40
-35
-35
-30
TX1+ 9
20 TXOUT
150Ω TXCT 11
100 Ω
4 FOUT
LPF
150Ω
-20
-20
-38
12 TPHB
Schematic
FIN 1
-30
19 TXOUTL
TX1- 10
13 TPHA
150Ω
15 RPHB
FINL 2
5 FOUT
18 RXIN
RX0+ 6
FGND 3
150Ω
100 Ω
RXCT 8
17 RXINL
RX0- 7
Package
14 RPHA
A
Dimensions
B
Dim.
A
B
C
D
E
F
G
H
I
J
K
L
Pin 1 I.D.
C
PCA
EPT7076
Date Code
J
L
H
E
K
F
I
G
(Inches)
Min. Max. Nom.
(Millimeters)
Min. Max. Nom.
1.090
.260
.380
--.010
----.016
.008
--.130
---
27.69
6.60
9.65
--.254
----.406
.203
--3.30
---
1.110
.280
.400
--.030
----.022
.012
--.150
---
1.100
.270
.390
.950
.020
.050
.135
.020
.010
.075
.140
.100
28.19
7.11
10.16
--.762
----.559
.305
--3.81
---
27.94
6.85
9.91
24.13
.508
1.27
3.43
.508
.254
1.91
3.56
2.54
D
PCA ELECTRONICS, INC.
16799 SCHOENBORN ST.
NORTH HILLS, CA 91343
CST7076a
Rev. B1
1/19/99
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
EPT7076
ELECTRONICS INC.
The circuit below is a guideline for interconnecting PCA’s EPT7076 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.
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 EPT7076. There need not be any ground plane beyond this
point.
For best results, PCB designer should design the outgoing traces preferably to be 50 ohms, balanced and well coupled to
achieve minimum radiation from these traces.
Typical Application Circuit Connection to TI380C60 (or Equivalent) For NIC.
Rcv+
18
4
7
17
5
15
20
3
14
19
6
150Ω
6
PH-B
Rcv+5V
PH-A
+5V
Xmit±
1
50Ω/2W
PHOUTA
Rcv±
13
2
RJ4
5
7
8
8
50Ω/2W
PHOUTB
10µF
12
10µF
4
TI380C60
5
10
100Ω
100Ω
442Ω
Xmit+
Xmit-
3
9
EPT7076
1
11
2
Notes : 1. Pins 15 & 14 are left unconnected. Applications vary. Your system may have a phantom drive return
detection circuit needing pins 15 & 14 to be connected separately or together, can be taken to ground
via an inductor.
PCA ELECTRONICS, INC.
16799 SCHOENBORN ST.
NORTH HILLS, CA 91343
CST7076b
Rev. B1 1/19/99
TEL: (818) 892-0761
FAX: (818) 894-5791
http://www.pca.com