Si2401
Preliminary Rev. 0.9
63
Reset settings
=
0000_0000 (0x00)
SF5 (DAA5). DAA Low Level Functions 5
Bit
D7
D6
D5
D4
D3
D2
D1
D0
Name
OHS[1:0]
ILIM
RZ
RT
Type
R/W
R/W
R/W
R/W
Bit
Name
Function
7:6
Reserved
Read returns zero.
5:4
OHS[1:0]
On-Hook Speed.
These bits set the amount of time for the line-side device to go on-hook. The on-hook
speeds specified are measured from the time the register is written until loop current
equals zero.
OHS[1:0]
Mean On-Hook Speed
00
Less than 0.5 ms
01
3 ms ±10% (Meets ETSI standard)
1X
20 ms ±10% (Meets Australian spark quenching spec)
3
ILIM
Current Limiting Enable.
0 = Current limiting mode disabled.
1 = Current limiting mode enabled. This mode limits loop current to a maximum of 60 mA
per the TBR21 standard.
2
RZ
Ringer Impedance.
0 = Maximum (high) ringer impedance.
1 = Synthesized ringer impedance used to satisfy a maximum ringer impedance specifi-
cation in countries, such as Poland, South Africa, and Slovenia.
1
Reserved
Do not modify.
0
RT
Ringer Threshold Select.
Used to satisfy country requirements on ring detection. Signals below the lower level do
not generate a ring detection; Signals above the upper level are guaranteed to generated
a ring detection.
0 = 13.5 to 16.5 V
RMS
1 = 19.35 to 23.65 V
RMS
