SI3225-G-GQ Silicon Laboratories Inc, SI3225-G-GQ Datasheet - Page 99

• Manufacturer Part Number: SI3225-G-GQ
• Description: IC PROSLIC/CODEC DUAL 64TQFP
• Manufacturer: Silicon Laboratories Inc
• Series: ProSLIC®r

Specifications of SI3225-G-GQ

• Function: Subscriber Line Interface Concept (SLIC), CODEC
• Interface: GCI, PCM, SPI
• Number Of Circuits: 2
• Voltage - Supply: 3.3V, 5V
• Current - Supply: 65mA
• Power (watts): 941mW
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 64-TQFP, 64-VQFP
• Includes: Battery Switching, BORSCHT Functions, DTMF Generation and Decoding, FSK Tone Generation, Modem and Fax Tone Detection
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

Because each second-order filter stage is fully-
programmable, there are many other possible filter
implementations.
The IIR filter output is measured for power and peak
post-processing. The peak measurement window
duration is programmable by entering a value into the
TESTWLN RAM address. The peak value (TESTPKO)
is updated at the end of each window period. Power
measurement is performed by using a single-pole IIR
filter to average the output of the sixth-order IIR filter.
Programmable timer. The Dual ProSLIC devices
incorporate several digital oscillator circuits to
program the on and off times of the ringing and
pulse-metering signals. The tone generation
oscillator can be used to program a time period for
averaging specific measured test parameters.
Transmit audio path diagnostics filter. Transmit
path audio diagnostics are facilitated by
implementing a sixth-order IIR filter followed by peak
detection and power estimation blocks. This filter
can be programmed to eliminate or amplify specific
signals for the purpose of measuring the peak
amplitude and power content of individual
components in the audio spectrum. Figure 11 on
page 25 illustrates the location of the diagnostics
filter block.
The sixth order IIR filter operates at an 8 kHz sample
rate and is implemented as three second-order filter
stages in cascade. Each second-order filter offers
five fully-programmable coefficients (a1, a2, b0, b1,
and b2) with 25-bit precision by providing several
user-accessible registers. Each filter stage is
implemented with the following format:
If any of the second-order filter stages are not
required, they can be programmed to H(z) = 1 by
setting a1 = 0, a2 = 0, b0 = 1, b1 = 0, and b2 = 0.
This flexible filter block can be programmed with the
following characteristics:
the presence of a single tone. 90 dB attenuation is
provided at the notched frequency. Implemented by
placing two 0s on the unit circle at the notch frequency
and two poles inside the unit circle at the notch
frequency.
presence of dual tones.
particular harmonic in the presence of a single tone.
intermodulation product in the presence of dual tones.
Single notch. Used for measuring noise/distortion in
Dual notch. Used for measuring noise/distortion in the
Single notch/single peak. Used for measuring a
Dual notch/single peak. Used to measure a particular
H z ( )
=
(
------------------------------------------------------- -
(
b0
1 a1z
–
+
b1z
–
–
1
1
–
+
a2z
b2z
–
–
2
2
)
)
Rev. 1.3
The power averaging filter time constant is absolute
value programmable, and the average power result is
read from the TESTAVO RAM location.
3.32.5. Diagnostics Capabilities
Foreign voltages test. The Dual ProSLIC devices
can detect the presence of foreign voltages
according to GR-909 requirements of ac voltages >
10 V and dc voltages > 6 V from T-G or R-G. This
test is performed when it has been determined that a
hazardous voltage is not present on the line.
Resistive faults (leakage current) test. Resistive
fault conditions are measured from T-G, R-G, or T-R
for dc resistance per GR-909 specifications. If the dc
resistance is < 150 kΩ, it is considered a resistive
fault. To perform this test, program the Dual ProSLIC
chipset to generate a constant open-circuit voltage,
and measure the resulting current. The resistance is
then calculated.
Receiver off-hook test. Uses a similar procedure
as described in the resistive faults test above but is
measured across T-R only. In addition, two
measurements must be performed at different open-
circuit voltages to verify the resistive linearity. If the
calculated resistance has more than 15%
nonlinearity between the two calculated points and
the voltage/current origin, it is determined to be a
resistive fault.
Ringers (REN) test. Verifies the presence of REN at
the end of the TIP/RING pair per GR-909
specifications. It can be implemented by generating
a 20 Hz ringing signal between 7 V
and measuring the 20 Hz ac current using the 8-bit
monitor ADC. The resistance (REN) can then be
calculated using the software module. The
acceptable REN range is >0.175 REN (<40 kΩ) or
<5 REN (>1400 Ω). A returned value of <1400 Ω is
determined to be a resistive fault from T-R, and a
returned value >40 kΩ is determined to be a loop
with no handset attached.
AC line impedance measurement. Determines the
ac loop impedence across T-R. It can be
implemented by sending out multiple discrete tones,
one at a time, and measuring the returned amplitude
with the hybrid balance filter disabled. By calculating
the voltage difference between the initial amplitude
and the received amplitude and dividing the result by
the audio current, the line impedance can then be
calculated.
Si3220/25 Si3200/02
rms
and 17 V
rms
99