CC2510FX Datasheet, PDF (217/253 Pages) List of Unclassifed Manufacturers – True System-on-Chip with Low Power RF Transceiver and 8051 MCU

CC2510Fx / CC2511Fx
There is a trade off between blanking time and
memory space needed for storing calibration
data in non-volatile memory. Solution 2) above
gives the shortest blanking interval, but
requires more memory space to store
calibration values. Solution 3) gives
approximately 570 µs smaller blanking interval
than solution 1).
15.18.3 Wideband Modulation not Using
Spread Spectrum
Digital modulation systems under FCC part
15.247 includes FSK and GFSK modulation.
A maximum peak output power of +30 dBm is
allowed if the 6 dB bandwidth of the modulated
signal is not less than 500 kHz. In addition, the
peak power spectral density conducted to the
antenna shall not be greater than +8 dBm in
any 3 kHz band.
Operating at high data rates and high
frequency separation, the CC2500 is suited for
systems targeting compliance with digital
modulation system as defined by FCC part
15.247. An external power amplifier is needed
to increase the output above +0 dBm.
15.18.4 Data Burst Transmissions
The high maximum data rate of
CC2510Fx/CC2511Fx opens up for burst
transmissions. A low average data rate link
(say 10 kbps), can be realized using a higher
over-the-air data rate. Buffering the data and
transmitting in bursts at high data rate (say
500 kbps) will reduce the time in active mode,
and hence also reduce the average current
consumption significantly. Reducing the time
in active mode will reduce the likelihood of
collisions with other systems, e.g. WLAN.
15.18.5 Continuous Transmissions
In data streaming applications the
CC2510Fx/CC2511Fx opens up for continuous
transmissions at 500 kbps effective data rate.
As the modulation is done with an I/Q up-
converter 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.)
15.18.6 Crystal Drift Compensation
The CC2510Fx/CC2511Fx has a very fine
frequency resolution. This feature can be used
to compensate for frequency offset and drift.
The frequency offset between an ‘external’
transmitter and the receiver is measured in the
CC2510Fx/CC2511Fx and can be read back from
the FREQEST status register. The measured
frequency offset can be used to calibrate the
frequency using the ‘external’ transmitter as
the reference. That is, the received signal of
the device will match the receiver’s channel
filter better. In the same way the centre
frequency of the transmitted signal will match
the ‘external’ transmitter’s signal.
15.18.7 Spectrum Efficient Modulation
CC2510Fx/CC2511Fx also has the possibility to
use Gaussian shaped FSK (GFSK). This
spectrum-shaping feature improves adjacent
channel power (ACP) and occupied
bandwidth. In ‘true’ FSK systems with abrupt
frequency shifting, the spectrum is inherently
broad. By making the frequency shift ‘softer’,
the spectrum can be made significantly
narrower. Thus, higher data rates can be
transmitted in the same bandwidth using
GFSK.
15.18.8 Low Cost Systems
As the CC2510Fx/CC2511Fx provides 500 kbps
multi-channel performance without any
external filters, a very low cost system can be
made.
A differential antenna will eliminate the need
for a balun, and the DC biasing can be
achieved in the antenna topology, see Figure
7.
A HC-49 type SMD crystal is used in the
CC2510Fx EM reference design. Note that the
crystal package strongly influences the price.
In a size constrained PCB design a smaller,
but more expensive, crystal may be used.
15.18.9 Battery Operated Systems
In low power applications, the low power
modes PM2 or PM3 with should be used when
the CC2510Fx/CC2511Fx is not active.
The Sleep Timer Wake-on-Radio functionality
should be used in low power applications.
15.18.10
Increasing Output Power
In some applications it may be necessary to
extend the link range. Adding an external
power amplifier is the most effective way of
doing this.
The power amplifier should be inserted
between the antenna and the balun, and two
CC2510Fx/CC2511Fx PRELIMINARY Data Sheet (Rev. 1.2) SWRS055A Page 217 of 252