SI2109-D-FMR Silicon Laboratories Inc, SI2109-D-FMR Datasheet - Page 20

• Manufacturer Part Number: SI2109-D-FMR
• Manufacturer: Silicon Laboratories Inc

Specifications of SI2109-D-FMR

• Operating Temperature (min): 0C
• Operating Temperature (max): 70C
• Operating Temperature Classification: Commercial
• Lead Free Status / Rohs Status: Supplier Unconfirmed

Si2107/08/09/10
5.2. Demodulator
The
demodulation of channels between 1 to 45 Mbaud. It
incorporates the following functional blocks: analog-to-
digital converters (ADCs), dc notch filters, I/Q imbalance
corrector, decimation filters, matched filters, equalizer,
digital automatic gain controls, and a soft-decision
decoder. The demodulator supports rapid channel
acquisition using an advanced carrier offset estimation
algorithm. When combined with the Si2109/10’s blind
scanning capabilities, the device becomes an ideal
solution for the free-to-air (FTA) and common interface
(CI) market. Automatic acquisition and fade recovery
sequencers are also included to reduce the required
amount of software interaction and to simplify the
overall design. The output of the demodulator is
quantized into a 4-bit number by the soft-decision
decoder. The use of soft-decision decoding improves
the error correction capabilities of the channel decoder.
5.3. DVB-S/DSS Channel Decoder
The Si2107/08/09/10 integrates a full-channel decoder,
which can be configured in either DSS or DVB-S mode
and consists of a soft-decision Viterbi decoder, de-
interleaver,
dispersal descrambler.
5.3.1. Viterbi decoder
The Viterbi decoder performs maximum likelihood
estimation of convolutional codes in compliance with
DVB-S and DSS standards. The decoder is capable of
detecting code rate, puncturing pattern phase, 90°
phase rotation, and I/Q interchange. Supported code
rates are listed in Table 14.
The device allows monitoring of the Viterbi bit-error rate
(BER) over a finite or infinite measurement window.
20
demodulator
Table 14. Viterbi Code Rates
Reed-Solomon
DVB-S
1/2
2/3
3/4
5/6
7/8
—
supports
decoder,
QPSK
DSS
1/2
2/3
6/7
—
—
—
and
and
energy-
BPSK
Rev. 1.0
5.3.2. Convolutional De-Interleaver
The deinterleaver disassembles the Reed-Solomon
(RS) code words, which were interleaved by the
modulator, to provide better resilience against burst
errors. The Si2107/08/09/10 performs deinterleaving
according to DVB-S and DSS standards.
5.3.3. Reed-Solomon Decoder
The Si2107/08/09/10 supports RS codes in compliance
with DVB-S and DSS specifications. Both standards use
a shortened Reed-Solomon code, which can correct up
to eight byte errors per information packet. DVB-S
utilizes 204 byte codes. DSS utilizes 146 byte codes.
The device allows monitoring of correctable bit,
correctable byte, and uncorrectable packet errors over a
finite or infinite measurement window. The device also
includes a total BER monitor, which compares received
data from a modulated PRBS sequence against the
same sequence generated from an on-chip PRBS
generator.
5.3.4. Energy-Dispersal Descrambler
The descrambler removes the energy dispersal
scrambling introduced by the DVB-S process. The
descrambler is automatically bypassed in DSS mode.
5.4. On-Chip Blindscan Controller: Quick-
The device includes on-chip QuickScan circuitry to
facilitate extremely fast detection of available satellite
channels. For each valid DVB-S/DSS channel, the
tuning frequency and symbol rate, which can be stored
by the host for subsequent tuning, are determined. On
Si2107/08 devices, the host needs to provide the
channel tuning frequency and symbol rate to the device.
5.5. LNB Signaling Controller
The device supports several LNB signaling methods
including dc voltage selection, continuous tone, tone
burst,
messaging, and several combinations of these to allow
simultaneous operation with legacy tone/burst and
DiSEqC-capable peripherals.
Si2107/09 includes the capability to convert I
signaling commands to signals that interface to an
external LNB supply regulator circuit. In the case of (bi-
directional) DiSEqC operation, the device modulates
(and demodulates) the PWK data to (and from) an
internal message FIFO, which the host uses to write
(and read) DiSEqC messages. In the case of
transmission, the device can generate either the 22 kHz
tone burst directly or generate a tone envelope for when
an external LNB supply controller is used, which
includes the 22 kHz oscillator.
Scan (Si2109/10 Only)
DiSEqC
1.x-
and
DiSEqC
2.x-compliant
2
C