Bt8370/8375/8376
Fully Integrated T1/E1 Framer and Line Interface
3.11 Transmit LIU Registers
Table 3-14. Return Loss Values
V
PK
TURNS
TERM
R
R (dB)
Remarks
TERM
L
(Normalized)
Pulse[2:0] = 75 Ω Cable Selection
0
0
0
1
0
1
1
0
None
51.1
40.5
None
0
1.00
1.00
0.89
1.00
Iout scaled for 1:1.36
–18
–65
0
Compromise match
Impedance match
Iout scaled for 1:1.15
Pulse[2:0] = 100 Ω Cable Selection
0
0
0
1
0
1
1
0
None
51.1
54.1
None
0
1.00
1.00
1.03
1.00
Iout scaled for 1:1.36
Compromise match
Impedance match
–32
–76
0
Iout scaled for 1:1.15
Pulse[2:0] = 120 Ω Cable Selection
0
0
0
1
0
1
1
0
None
51.1
64.9
None
0
1.00
1.00
1.13
1.00
Iout scaled for 1:1.36
Compromise match
Impedance match
–18
–74
0
Iout scaled for 1:1.15
LBO[1:0]
Select Line Build Out—Up to three LBO networks can be placed in line with the transmitter to
attenuate XTIP/XRING outputs in 7.5 dB steps, per the signal transfer function defined by
FCC Part 68 regulations. (Refer to Figure 2-41 through Figure 2-44 for LBO isolated pulse
templates, which are applicable only while PULSE[2:0] = 111).
LBO
00
Attenuation @ 772 kHz
0.0 dB
FCC Option
Option A
01
7.5 dB
Option B
10
15.0 dB
Option C
11
22.5 dB
Final Span Target Loss
N8370DSE
Conexant
3-65
CONEXANT [ CONEXANT SYSTEMS, INC ]
