SI3050-KT Silicon Laboratories Inc, SI3050-KT Datasheet - Page 29

• Manufacturer Part Number: SI3050-KT
• Description: IC VOICE DAA GCI/PCM/SPI 20TSSOP
• Manufacturer: Silicon Laboratories Inc
• Type: Chipsetr

Specifications of SI3050-KT

• Package / Case: 20-TSSOP
• Function: Data Access Arrangement (DAA)
• Interface: PCM, Serial, SPI
• Number Of Circuits: 1
• Voltage - Supply: 3 V ~ 3.6 V
• Current - Supply: 8.5mA
• Operating Temperature: 0°C ~ 70°C
• Mounting Type: Surface Mount
• Includes: Line Voltage Monitor, Loop Current Monitor, Overload Detection, Parallel Handset Detection, Polarity Reversal Detection, TIP and
• Product: Modem Chip
• Supply Voltage (min): 3 V
• Supply Current: 8.5 mA
• Maximum Operating Temperature: + 70 C
• Minimum Operating Temperature: 0 C
• Mounting Style: SMD/SMT
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Power (watts): -
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant, Contains lead / RoHS non-compliant

DC Termination
The DAA has programmable settings for the dc
impedance, current limiting, minimum operational loop
current and TIP/RING voltage. The dc impedance of the
DAA is normally represented with a 50 Ω slope as
shown in Figure 21, but can be changed to an 800 Ω
slope by setting the DCR bit. This higher dc termination
presents a higher resistance to the line as loop current
increases.
For applications requiring current limiting per the TBR21
standard, the ILIM bit may be set to select this mode. In
this mode, the dc I/V curve is changed to a 2000 Ω
slope above 40 mA, as shown in Figure 22. This allows
the DAA to operate with a 50 V, 230 Ω feed, which is the
maximum linefeed specified in the TBR21 standard.
Figure 22. TBR21 Mode I/V Characteristics,
Figure 21. FCC Mode I/V Characteristics,
20
45
40
35
30
25
15
10
12
11
10
5
.015 .02 .025 .03 .035 .04 .045 .05 .055 .06
8
9
7
6
.01 .02 .03 .04 .05 .06 .07 .08 .09 .1 .11
DCV[1:0]
DCV[1:0]
TBR21 DCT Mode
Loop Current (A)
=
=
Loop Current (A)
FCC DCT Mode
11, MINI[1:0]
11, MINI[1:0]
=
=
00
00
Rev. 1.0
The MINI[1:0] bits select the minimum operational loop
current for the DAA, and the DCV[1:0] bits adjust the
DCT pin voltage, which affects the TIP/RING voltage of
the DAA. These bits allow important trade-offs to be
made
operational loop current. Increasing TIP/RING voltage
increases signal headroom, whereas decreasing the
TIP/RING voltage allows compliance to PTT standards
in low-voltage countries, such as Japan. Increasing the
minimum operational loop current above 10 mA also
increases signal headroom and prevents degradation of
the signal level in low-voltage countries.
AC Termination (Si3018 Line-Side Only)
The Si3050 has four ac termination impedances when
used with the Si3018 line-side device. The ACIM[3:0]
bits in Register 30 are used to select the ac impedance
setting on the Si3018. The four available settings for the
Si3018 are listed in Table 17. If an ACIM[3:0] setting
other than the four listed in Table 17 is selected, the ac
termination is forced to 600 Ω (ACIM[3:0] = 0000). The
programmable digital hybrid can be used to further
reduce near-end echo for each of the four listed ac
termination settings. See "Transhybrid Balance" on
page 36 for details.
AC Termination (Si3019 Line-Side Only)
The Si3050 has sixteen real and complex ac
termination impedances when used with the Si3019
line-side device. The ACIM[3:0] bits in Register 30 are
used to select the ac impedance setting on the Si3019.
The sixteen available settings for the Si3019 are listed
in Table 18.
The most widely used ac terminations are available as
register
requirements. The real 600 Ω impedance satisfies the
requirements of FCC Part 68, JATE, and other country
requirements. The 270 Ω + (750 Ω || 150 nF) satisfies
the requirements of TBR21.
There
non-standard
350 Ω + (1000 Ω || 210 nF) impedance selection in
Register 30 is the ANSI/EIA/TIA 464 compromise
ACIM[3:0]
Table 17. AC Termination Settings for the
0000
0100
0011
1111
between
are
options
600 Ω
220 Ω + (820 Ω || 120 nF) and 220 Ω +
(820 Ω || 115 nF)
370 Ω + (620 Ω || 310 nF)
Global complex impedance
Si3018 Line-Side Device
two
ac
signal
to
selections
termination
satisfy
AC Termination
headroom
useful
various
requirements.
and
Si3050
for
global
satisfying
minimum
PTT
The
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