Si3056
Si3018/19/10
Register 26. DC Termination Control
Bit
D7
DCV[1:0]
R/W
D6
D5
MINI[1:0]
R/W
D4
D3
D2
D1
D0
Name
Type
ILIM
R/W
DCR
R/W
Reset settings = 0000_0000
Bit
7:6
Name
DCV[1:0] TIP/RING Voltage Adjust.
Function
Adjust the voltage on the DCT pin of the line-side device, which affects the TIP/RING voltage
on the line. Low voltage countries should use a lower TIP/RING voltage. Raising the TIP/
RING voltage improves signal headroom.
DCV[1:0] DCT Pin Voltage
00
01
10
11
3.1 V
3.2 V
3.35 V
3.5 V
5:4
MINI[1:0] Minimum Operational Loop Current.
Adjusts the minimum loop current so the DAA can operate. Increasing the minimum opera-
tional loop current improves signal headroom at a lower TIP/RING voltage.
MINI[1:0] Min Loop Current
00
01
10
11
10 mA
12 mA
14 mA
16 mA
3:2 Reserved Do not write to these register bits.
1
ILIM
Current Limiting Enable.
0 = Current limiting mode disabled.
1 = Current limiting mode enabled. Limits loop current to a maximum of 60 mA per the TBR21
standard.
DC Impedance Selection.
0
DCR
0 = 50 Ω dc termination is selected. Use this mode for all standard applications.
1 = 800 Ω dc termination is selected.
Rev. 1.05
69
SILICON [ SILICON ]
