si2401 Silicon Laboratories, si2401 Datasheet - Page 66

• Manufacturer Part Number: si2401
• Description: V.22bis Isomodem With Integrated Global Daa
• Manufacturer: Silicon Laboratories

Si2401
SF6 (DAA6). DAA Low Level Functions 6
Reset settings = 1111_0000 (0xF0)
66
Bit
7:6
5:4
3:0
Name
Type
Bit
MINI[1:0]
DCV[1:0]
ACT[3:0]
Name
D7
MINI[1:0]
R/W
Minimum Operational Loop Current.
Adjusts the minimum loop current at which the DAA can operate. Increasing the mini-
mum operational loop current can improve signal headroom at a lower TIP/RING volt-
age.
TIP/RING Voltage Adjust.
These bits 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 volt-
age. Raising the TIP/RING voltage can improve signal headroom.
AC Termination Select.
MINI[1:0]
DCV[1:0]
ACT[3:0]
D6
00
01
10
11
00
01
10
11
0000
0011
0100
1111
AC Termination
Min Loop Current
DCT Pin Voltage
3.1 V
3.2 V
3.35 V
3.5 V
Real 600 Ω termination that satisfies the impedance requirements
of FCC part 68, JATE, and other countries.
Global complex impedance. Complex impedance that satisfies global
impedance requirements EXCEPT New Zealand. May achieve higher
return loss for countries requiring complex ac termination.
[220 Ω + (820 Ω || 120 nF) and 220 Ω + (820 Ω || 115 nF)].
Complex impedance for use in New Zealand.
[370 Ω + (620 Ω || 310 nF)]
Complex impedance that satisfies global impedance requirements.
D5
10 mA
12 mA
14 mA
16 mA
DCV[1:0]
R/W
Rev. 1.0
D4
Function
D3
D2
ACT[3:0]
R/W
D1
D0