Si3056
Si3018/19/10
Register 30. AC Termination Control (Si3019 line-side device only)
Bit
D7
D6
D5
D4
D3
D2
D1
D0
Name
Type
FULL2
R/W
ACIM[3:0]
R/W
Reset settings = 0000_0000
Bit Name
7:5 Reserved Read returns zero.
Function
4
FULL2
Enhanced Full Scale (2X) Transmit and Receive Mode (Si3019 line-side Revision E or
later).
0 = Default
1 = Transmit/Receive 2X Full Scale
This bit changes the full scale of the ADC and DAC from 0 min to +6 dBm into 600 Ω load (or
1.5 dBV into all reference impedances). When this bit is set, the DCV[1:0] bits (Register 26)
should be set to all 1s to avoid distortion at low loop currents.
3:0 ACIM[3:0] AC Impedance Selection (Si3019 line-side device only).
The off-hook ac termination is selected from the following:
0000 = 600 Ω
0001 = 900 Ω
0010 = 270 Ω + (750 Ω || 150 nF) (TBR21) and 275 Ω + (780 Ω || 150 nF)
0011 = 220 Ω + (820 Ω || 120 nF) (Australia/New Zealand) and 220 Ω + (820 Ω || 115 nF)
(Slovakia/Slovenia/South Africa/Germany/Austria/Bulgaria)
0100 = 370 Ω + (620 Ω || 310 nF) (New Zealand #2/India)
0101 = 320 Ω + (1050 Ω || 230 nF) (England)
0110 = 370 Ω + (820 Ω || 110 nF)
0111 = 275 Ω + (780 Ω || 115 nF)
1000 = 120 Ω + (820 Ω || 110 nF)
1001 = 350 Ω + (1000 Ω || 210 nF)
1010 = 0 Ω + (900 Ω || 30 nF) (line-side Revision C or earlier)
1010 = 200 Ω + (680 Ω || 100 nF) (China) (line-side Revision E or later)
1011 = 600 Ω + 2.16 µF
1100 = 900 Ω + 1 µF
1101 = 900 Ω + 2.16 µF
1110 = 600 Ω + 1 µF
1111 = Global impedance
Rev. 1.05
71
SILICON [ SILICON ]
