SI2107-X-FM SILABS [Silicon Laboratories], SI2107-X-FM Datasheet - Page 21

• Manufacturer Part Number: SI2107-X-FM
• Description: SATELLITE RECEIVER FOR DVB-S/DSS WITH QUICKLOCK AND QUICKSCAN
• Manufacturer: SILABS [Silicon Laboratories]

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
Preliminary Rev. 0.81
2
C
5.6. On-Chip LNB DC-DC Step-Up
Next to the LNB message signaling controller, the
device also integrates the LNB supply regulator
controller.
architecture consists of a step-up dc-dc (boost)
converter followed by an efficient filter, linefeed, and
DiSEqC transmit/receive circuit, which implements a
very power-efficient LNB supply solution. This facilitates
a complete LNB supply circuit with only a minimal
number of external components.
5.7. Crystal Oscillator
The crystal oscillator requires a crystal with a resonant
fundamental frequency of 20 MHz to generate the
reference frequency for the local oscillator. A single
crystal can be shared between two devices by utilizing
the master-slave configuration shown in Figure 11.
Controller (Si2108/10 Only)
Figure 11. Master-Slave Crystal Sharing
The
XTAL1
XTAL2
XTOUT
Y1
supported
Si2107/08/09/10
C11
C12
LNB
XTAL1
supply
regulator
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