SI3200-BS Silicon Laboratories Inc, SI3200-BS Datasheet - Page 46

• Manufacturer Part Number: SI3200-BS
• Description: IC LINEFEED INTRFC 100V 16SOIC
• Manufacturer: Silicon Laboratories Inc
• Series: ProSLIC®r

Specifications of SI3200-BS

• Function: Subscriber Line Interface Concept (SLIC), CODEC
• Interface: GCI, PCM, SPI
• Number Of Circuits: 2
• Voltage - Supply: 3.3V, 5V
• Current - Supply: 110µA
• Power (watts): 941mW
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 16-SOIC (3.9mm Width)
• Includes: Battery Switching, BORSCHT Functions, DTMF Generation and Decoding, FSK Tone Generation, Modem and Fax Tone Detection
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant

Si3232
4.13. Two-Wire Impedance Synthesis
Two-wire impedance synthesis is performed on-chip to
optimally match the output impedance of the Si3232 to
the impedance of the subscriber loop, thus minimizing
the receive path signal reflected back onto the transmit
path. The Si3232 provides on-chip selectable analog
two-wire impedances to meet return loss requirements.
The subscriber loop varies with any series impedance
due to protection devices placed between the Si3200
outputs and the TIP/RING pair according to the
following equation:
Where:
Therefore, the user must also consider the value of
R
impedance.
The Si3232’s analog impedance synthesis scheme is
sufficient for many short loop applications. If a unique
complex ac impedance is required, the Si3232’s
impedance scheme must be augmented or replaced by
a DSP-based impedance generator. To turn off the
analog impedance coefficients (RS, ZP, and ZZ), set the
ZSDIS bit of the ZZ register to 0.
46
PROT
when
Z
to the TIP/RING pair
R
protection devices
R
impedance
T
PROT
A
is the termination impedance presented
is the analog portion of the selected
programming
V
-10
-20
-30
-40
-50
Z
TIP/RING
0
T
is the series resistance caused by
0
=
Set VOCZERO bit to 1
Figure 23. Wink Function with Programmable Ramp Rate
2R
(V)
PROT
10
+
the
R
A
20
on-chip
2V/125 µs slope
set by RAMP bit
30
Preliminary Rev. 0.96
Set VOCZERO bit to 0
analog
40
4.13.1. Transhybrid Balance Filter
The Si3232 is intended to be used with DSP-based
codecs that provide the transhybrid balance function.
No transhybrid capability exists in the Si3232.
4.13.2. Pulse Metering Generation
The Si3232 offers an internal tone generator suitable for
generating tones above the audio frequency band. This
oscillator is provided for the generation of billing tones
which are typically 12 kHz or 16 kHz. The equations for
calculating the pulse metering coefficients are as
follows:
50
Figure 24. Two-Wire Impedance Simplified
Z
L
60
Z
RING
T
TIP
Coeff = cos (2πf/64000 Hz)
PMFREQ = coeff
70
V
V
V
R
R
cm
oc
ov
PROT
PROT
V
80
Circuit
RING
V
V
BAT
TIP
Time (ms)
•
(2
14
– 1)
Si3232