CC2400 Chipcon AS, CC2400 Datasheet - Page 49

• Manufacturer Part Number: CC2400
• Description: 2.4 GHz RF Transceiver
• Manufacturer: Chipcon AS

System Considerations and Guidelines
SRD regulations
International regulations and national laws
regulate the use of radio receivers and
transmitters. SRDs (Short Range Devices)
for license free operation are allowed to
operate in the 2.45 GHz bands worldwide.
The most important regulations are EN
300 440 (Europe), FCC CFR47 part
15.247 and 15.249 (USA), and ARIB STD-
T66 (Japan).
Frequency hopping and multi-channel
systems
The 2.400 – 2.4835 GHz band is shared
by many systems both in industrial, office
and home environment. It is therefore
recommended to use frequency hopping
spread spectrum (FHSS) or a multi-
channel protocol because the frequency
diversity makes the system more robust
with respect to interference from other
systems operating in the same frequency
band.
CC2400
channel systems due to its agile frequency
synthesizer and effective communication
interface. Using the packet handling
support
beneficial in such systems as these
features will significantly offload the host
controller.
Due to the low-IF I/Q receiver and the on-
chip complex filtering, the image channel
will be significantly rejected. This is
important for all 2.4GHz systems.
Data burst transmissions
The high maximum data rate of
opens up for burst transmissions. A low
average data rate link (say 10 kbps), can
be realized using a higher over-the-air
data
transmitting in bursts at high data rate (say
1 Mbps) will reduce the time in active
mode, and hence also reduce the average
current consumption significantly.
Continuous transmissions
In data streaming applications the
opens up for continuous transmissions at
1 Mbps effective data rate. A typical
application is digital audio systems. As the
Chipcon AS
rate.
is highly suited for FHSS or multi-
and
SmartRF
Buffering
data
®
CC2400 PRELIMINARY Datasheet (rev. 1.1), 2003-10-02
buffering
the
data
is
CC2400
CC2400
also
and
SmartRF
modulation
upconverter with LO I/Q-signals coming
from a closed loop PLL, there is no
limitation in the length of a transmission.
(Open loop modulation used in some
transceivers often prevents this kind of
continuous data streaming and reduces
the effective data rate.)
Crystal drift compensation
A unique feature in
frequency
MDMCTRL.MOD_OFFSET[5:0].
feature can be used to compensate for
frequency
compensation affects both the
and the transmitter of the device being
compensated. I.e. the received signal of
the device will match the receiver’s
channel filter better. In the same way the
center frequency of the transmitted signal
will match the ‘external’ transmitter’s
signal.
Initial adjustment can be done using this
frequency
eliminates the need for an expensive
TCXO and trimming in some applications.
The frequency offset between an ‘external’
transmitter and the receiver is measured
in the
an
(FREQEST.RX_FREQ_OFFSET[7:0]).
The measured frequency offset can thus
be used to calibrate the frequency using
the ‘external’ transmitter as the reference.
See also page 40 (Automatic Frequency
Control).
This feature can also be used for
temperature compensation of the crystal if
the temperature drift curve is known and a
temperature sensor is included in the
system.
In less demanding applications, a crystal
with low temperature drift and low aging
could
compensation.
Spectrum efficient modulation
CC2400
Gaussian shaped FSK (GFSK). This
spectrum-shaping
CC2400
also has the possibility to use
be
offset
is
and can be read back from
resolution
internal
programmability.
used
®
done
CC2400
feature
and
CC2400
without
with
is the very fine
using
drift.
Page 49 of 73
improves
an
receiver
register
further
This
This
The
the
I/Q