 Conforms to Chinese National Standards
(GB/T20683-2011, GB/T20686-2011) |
|
The CXD2840ER meets all the receiver
performance stipulated by the Chinese
national standards (GB/T20683-2011, GB/T20686-2011). The Chinese national standard
will be formally enacted in November 2011
and Sony is one of the first companies to
receive national standard certification for its
demodulator IC. (See photograph 1.) Not only
does it support the seven modes stipulated
by the Chinese national standards, it also
exhibits superlative receiver performance
even for the parameters used in Hong Kong. |
| Improved Multipath Performance |
|
Since reflected waves are present during
reception of terrestrial broadcasts,
demodulator ICs must be able to deal with
multipath environment. Indoor antennas are
used in China to receive terrestrial broadcasts,
which makes reception more problematic.(See figure 1.)
The newly developed CXD2840ER has
even better multipath performance than the
CXD2830R, the current Sony product.
One improvement is better pre-echo tolerance.
(See figure 2.) The low position of antennas
mean that they receive a large amount of
reflected waves from adjacent buildings.
Since SFN (Single Frequency Network)
services have already started, not only delayed
waves but preceding waves (pre-echo) may
also be present. Another is the improvement
in dynamic multipath performance. (See
figure 3.) Since antennas are often installed
near streets, reception is often affected by
waves reflected off passing buses and cars
creating a continuously changing reception
environment.
Improvements in the adaptive filter algorithms
of the CXD2840ER allow it to handle quickly
changing reception environments. |
Improved Impulsive Noise
Tolerance
|
|
China is a vast country with widely varying
environments. For example, South China
lies in a subtropical region that is sometimes
exposed to severe weather conditions and
where violent thunder storms can cause
interference in the broadcasting system.
The CXD2840ER has been provided with
significantly better impulsive noise tolerance
than the current CXD2830R and can
withstand impulse noise that is up to 30 times
longer. (See table 1.) |
Compact Package and Reduced
Printed Circuit Board and BOM Costs
|
|
The CXD2840ER is provided in a compact
package (48-pin VQFN, 7 mm × 7 mm) and
runs on 3.3 V and 1.2 V power supplies. A
small mounting area simplifies the wiring
with the two power supplies. When combined
with a Sony silicon tuner IC (CXD2831WR),
the area occupied by the tuner on the board
can be minimized. This IC can select either
20.5 MHz or 41 MHz X'tal with a tolerance
of up to ±100 ppm. |
Tuner IC Chipset that Supports All the
World's Broadcasting Standards
|
|
Sony is the only manufacturer to develop
IC chipsets that support all the world's
broadcasting systems.
Since the CXD2840ER shares the package
and pin assignment with demodulator ICs for
other markets (CXD2836ER, CXD2835ER,
CXD2834ER, CXD2828ER and CXD2817ER)
that were developed during the same time
period, they are mutually replaceable. (See
figures 4 and 5.) Also, a shared software
interface will minimize man-hours spent on
examination and development. |
Second Generation DTMB and DVB-C Demodulator IC
for China that Combines Improvements in Functionality
and Performance with Compact Size
Vol.66