 Implements both DVB-T and DVB-C
Demodulation in a Single Chip |
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The CXD2817R is a multi-format demodulator
IC that supports both DVB-T (the terrestrial
digital broadcast standard) and DVB-C (the
digital cable broadcast standard). While Sony
led the industry in developing the first device
that integrated both DVB-T and DVB-C
demodulation functions on a single chip, Sony
has achieved both significant performance
improvements and added functionality in
the CXD2817R. Figure 1 shows the block
diagram of the CXD2817R. It is provided in a
7 × 7 mm2 48-pin LQFP package. |
| Demodulating Algorithms
that are Highly Resistant to
Multipath Interference |
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The CXD2817R incorporates demodulating algorithms that are highly resistant to
multipath interference and can handle a
variety of situations, including the transition
from the cessation of analog terrestrial
broadcasting to digital broadcasting and
the wide range of multipath environments
expected due to the changes in the broadcast
waveform environment due to the start of
DVB-T2 broadcasting. In particular, the
CXD2817R is extremely resistant even to
multipath that crosses over a guard interval,
which until now has been thought to be difficult
to handle, and it can be applied flexibly to SFN
(Single-Frequency Network) broadcasting,
which is likely to be more widely deployed in
future. (See figure 2.) |
Improved Adjacent Channel
Interference Rejection
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The CXD2817R prevents aliasing of adjacent
channel signals into the desired band due to
the sampling theorem and A/D conversion
by using a higher A/D converter sampling
frequency than existing models. This has
improved the adjacent channel interference
rejection characteristics. (See figure 3.) Not
only the CNR, which is a basic characteristic,
but also the impulse noise resistance, which is
expected to be standardized in the future, and
the CCI (co-channel interference) resistance
have been significantly improved. |
Extensive Set of Built-in
Functions, Including Automatic
Control Functions
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The CXD2817R also provides an automatic
recovery function that performs demodulation
synchronization control in the IC itself and
functions that support automatic detection
of spectrum inversions for use in each of
the DVB-T and DVB-C modes. These make
software development even easier. The
CXD2817R also makes even more accurate
monitoring of the received signal strength
possible by adding a 10-bit A/D converter for
signal strength monitoring. |
Support for a Wide Variety of
Interfaces
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The CXD2817R supports reception using
either a normal IF (DVB-T: 36.166 MHz,
DVB-C: 36.125 MHz) or a low-IF (about 5
MHz). It can also flexibly support a wide
variety of output formats, including TS output
as well as both serial and parallel outputs.
Since register settings and other aspects are
optimized assuming use with a Sony silicon
tuner IC, it can be used in end products with
only a minimal number of register settings. |
Low Power Consumption
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In combination with its high functionality,
the CXD2817R also supports low power
consumption applications. In particular, it
achieves the low power of 115 mW (typ.) in
DVB-T mode and 105 mW (typ.) in DVB-C
mode. Furthermore, power consumption can
be reduced to under 15 mW in sleep mode, in
which only the tuner control functions remain
active, and to under 0.15 mW in shutdown
mode, in which the crystal oscillator is
stopped. |
Cable and Terrestrial TV Digital
Broadcast Demodulator IC Achieves the
Industry‘s Top Class Performance
Vol.57