Rainbow Electronics DS26519 User Manual
Page 91
DS26519 16-Port T1/E1/J1 Transceiver
91 of 310
Figure 9-20. Network Connection—Longitudinal Protection
DS26518
TTIPn
TRINGn
RTIPn
RRINGn
S1
S2
S3
S4
S5
S6
S7
S8
T1
T2
T3
T4
2:1
1:1
F1
F2
F3
F4
TX
TIP
TX
RING
RX
TIP
RX
RING
560 pF
R
T
1 uF
NAME DESCRIPTION PART
MANUFACTURER
NOTES
1.25A Slow Blow Fuse
SMP 1.25
Bel Fuse
5
F1 to F4
1.25A Slow Blow Fuse
F1250T
Teccor Electronics
5
S1, S2
25V (max) Transient Suppressor
P0080SA MC
Teccor Electronics
1, 5
S3, S4, S5,
S6
180V (max) Transient Suppressor
P1800SC MC
Teccor Electronics
1, 4, 5
S7, S8
40V (max) Transient Suppressor
P0300SC MC
Teccor Electronics
1, 5
T1 and T2
Transformer 1:1CT and 1:2CT (3.3V, SMT)
PE-68678
Pulse Engineering
2, 3, 5
T3 and T4
Dual Common-Mode Choke (SMT)
PE-65857
Pulse Engineering
5
R
T
Termination Resistor (120
Ω, 110Ω, 100Ω, or
75
Ω)
— —
—
Note 1:
Changing S7 and S8 to P1800SC devices provides symmetrical voltage suppresion between tip, ring, and ground.
Note 2:
The layout from the transformers to the network interface is critical. Traces should be at least 25 mils wide and separated
from other circuit lines by at least 150 mils. The area under this portion of the circuit should not contain power planes.
Note 3:
Some T1 (never in E1) applications source or sink power from the network-side center taps of the Rx/Tx transformers.
Note 4:
The ground trace connected to the S3/S4 pair and the S5/S6 pair should be at least 50 mils wide to conduct the extra current
from a longitudinal power-cross event.
Note 5:
Alternative component recommendations and line interface circuits can be found by contacting
or in Application Note 324, wh
.
Note 6:
The 1
μF capacitor in series with TTIPn is only necessary for G.703 clock sync applications.
Note 7:
The 560pF on TTIPn/TRINGn must be tuned to your application.