SI3205-B-GS Silicon Laboratories Inc, SI3205-B-GS Datasheet - Page 27

• Manufacturer Part Number: SI3205-B-GS
• Description: IC PROSLIC LINE FEED 150V 16SOIC
• Manufacturer: Silicon Laboratories Inc
• Series: ProSLIC®r

Specifications of SI3205-B-GS

• On-hook Transmission: Yes
• Polarity Reversal: Yes
• On-chip Ring Relay Driver: No
• Longitudinal Balanced: 60
• Operating Supply Voltage (typ): 3.3V
• Operating Temp Range: -40C to 85C
• Package Type: TQFP
• Operating Temperature Classification: Industrial
• Mounting: Surface Mount
• Function: Subscriber Line Interface Concept (SLIC)
• Interface: GCI, PCM, SPI
• Number Of Circuits: 4
• Voltage - Supply: 3.3V
• Current - Supply: *
• Power (watts): *
• Operating Temperature: *
• Mounting Type: Surface Mount
• Package / Case: 16-SOIC (0.154", 3.90mm Width)
• Includes: *
• Lead Free Status / RoHS Status: Compliant

4.8. Ground Key Detection
The Dual ProSLIC provides a ground key detect
mechanism using a programmable architecture similar
to the loop closure scheme. The ground key detect
scheme provides two unique thresholds to allow
hysteresis and also includes a programmable debounce
filter to eliminate false detection. A ground key detect
status bit provides continuous status, and a maskable
interrupt bit is also provided.
4.9. Ringing Generation
The Dual ProSLIC provides the ability to generate a
programmable
waveform, with or without dc offset. The ringing
frequency, wave shape, cadence, and offset are all
register-programmable. Using a balanced ringing
scheme, the ringing signal is applied to both the TIP and
RING leads using dual ringing waveforms that are 180°
out of phase with each other. The resulting ringing
signal seen across TIP-RING is twice the amplitude of
the ringing waveform on either the TIP or RING lead,
which allows the ringing circuitry to be forced to
withstand only half the total ringing amplitude seen
across TIP-RING.
4.10. Polarity Reversal
The Dual ProSLIC supports polarity reversal for
message waiting and various other signaling modes.
The ramp rate can be programmed for a smooth or
abrupt transition to accommodate different application
requirements.
4.11. Two-Wire Impedance Synthesis
The ac two-wire impedance synthesis is generated on-
chip using a DSP-based scheme to optimally match the
output impedance of the Dual ProSLIC to the
impedance of the subscriber loop and minimize the
receive path signal reflected back onto the transmit
path. Most real or complex two-wire impedances can be
generated by using the coefficient generator software to
simulate the desired line conditions and generate the
required register coefficients.
4.12. Transhybrid Balance Filter
The trans-hybrid balance function is implemented on-
chip using a DSP-based scheme to effectively cancel
the reflected receive path signal from the transmit path.
The coefficient generator software is used to optimize
the filter coefficients.
sinusoidal
or
trapezoidal
Preliminary Rev. 0.33
ringing
4.13. Tone Generators
The Dual ProSLIC includes two digital tone generators
that allow a wide variety of single- or dual-tone
frequency and amplitude combinations. Each tone
generator has its own set of registers that hold the
desired frequency, amplitude, and cadence to allow
generation of DTMF and call progress tones for different
requirements. The tones can be directed to either
receive or transmit paths.
4.14. DTMF Detection
In DTMF, two tones generate a DTMF digit. One tone is
chosen from the four possible row tones, and one tone
is chosen from the four possible column tones. The sum
of these tones constitutes one of 16 possible DTMF
digits. The Dual ProSLIC performs DTMF detection
using an algorithm to compute the DFT for each of the
eight DTMF frequencies and their second harmonics. At
the end of the DFT computation, the squared
magnitudes of the DFT results for the 8 DTMF
fundamental tones are computed. The row and column
results are sorted to determine the strongest tones, and
checks are made to determine if the strongest row and
column tones constitute a DTMF digit.
4.15. DC-DC Controller
The controller converts a single positive dc input voltage
into an independent negative battery voltage for each
channel. The controller operates a dc-dc converter
circuit that converts a single positive dc input voltage
into an independent negative battery voltage for each
channel. In addition to eliminating external high-voltage
power supplies, the dc-dc controller allows the Dual
ProSLIC to dynamically control the battery voltage to
the minimum required for any given operating state
according to the programmed linefeed parameters.
4.16. Wideband Audio
The Si3226 supports a narrowband (200 Hz–3.4 kHz)
audio codec. The Si3227 supports a software-
selectable wideband (50 Hz–7 kHz) and narrowband
(200 Hz–3.4 kHz) audio codec. The Si3227 wideband
mode provides an expanded audio band at a 16-bit,
16 kHz sample rate for enhanced audio quality while
maintaining standard telephony audio compatibility.
Wideband audio samples are transmitted and received
on the PCM interface using two consecutive 8 kHz
frames.
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