CN8380 Datasheet, PDF (39/91 Pages) Conexant Systems, Inc – integrated quad line interface unit unit for both 1.544 Mbps (T1) and 2.048 Mbps (E1) applications

CN8380
Quad T1/E1 Line Interface
2.0 Circuit Description
2.4 Transmitter
Option C
Option C uses the standard 1:2 transformer and no parallel termination (Rt) for
T1 applications. In E1 applications, Rt is included because it is usually required to
provide a minimal level of line impedance matching. Series protection resistors
(Rs) are included. Option C is available only in Host Mode.
Table 2-6. Transmit Termination Option C
Application
Series Resistors
(Rs)
Parallel Termination
(Rt, Ω)
Return Loss
(dB)
T1—DSX-1
2 × 5.6 Ω
None
0
E1—75 Ω
2 × 5.6 Ω
114.8
–10
E1—120 Ω
2 ×5.6 Ω
190.0
–10
T1—I.431
2 × 5.6 Ω
None
0
NOTE(S):
1. Standard Transformer (1:2 turns ratio)
2. Hardware Mode: HTERM = 0
3. Host Mode: ALT_TR = 0, TERM = 0, T_BOOST = 1 [TLIU_CR; addr n2]
Option D
Option D uses the standard 1:2 transformer. A common parallel termination (Rt)
for both T1 and E1 applications is included to provide line impedance matching.
Series protection resistors (Rs) are also included. Option D is available in both
Host Mode and Hardware Mode.
Table 2-7. Transmit Termination Option D
Application
Series Resistors
(Rs)
Parallel Termination
(Rt, Ω)
Return Loss
(dB)
T1—DSX-1
2 × 5.6 Ω
21
–30
E1—75 Ω
2 × 5.6 Ω
21
–18
E1—120 Ω
2 × 5.6 Ω
21
–18
T1—I.431
2 × 5.6 Ω
21
–30
NOTE(S):
1. Standard Transformer (1:2 turns ratio)
2. Hardware Mode: HTERM = 1
3. Host Mode: ALT_TR = 0, TERM = 1, T_BOOST = 1 [TLIU_CR; addr n2]
N8380DSA
Conexant
2-17
Advance Information