CC1101IRHBRG4Q1 Datasheet, PDF (60/94 Pages) Texas Instruments – Low-Power Sub-1-GHz Fractional-N UHF Device Family for Automotive

CC11x1-Q1
SWRS076B – 11-07-22-013 - APRIL 2009 – REVISED APRIL 2010
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mode, data is transferred on a two wire serial interface. The CC11x1-Q1 provides a clock that is used to
set up new data on the data input line or sample data on the data output line. Data input (TX data) is the
GDO0 pin. This pin is automatically configured as an input when TX is active. The data output pin can be
any of the GDO pins (this is set by the IOCFG0.GDO0_CFG, IOCFG1.GDO1_CFG, and
IOCFG2.GDO2_CFG fields).
Preamble and sync word insertion/detection may or may not be active, dependent on the sync mode set
by the MDMCFG2.SYNC_MODE. If preamble and sync word is disabled, all other packet handler features
and FEC should also be disabled. The MCU must then handle preamble and sync word insertion and
detection in software. If preamble and sync word insertion/detection is left on, all packet handling features
and FEC can be used. One exception is that the address filtering feature is unavailable in synchronous
serial mode.
When using the packet handling features in synchronous serial mode, the CC11x1-Q1 inserts and detects
the preamble and sync word and the MCU only provides/gets the data payload. This is equivalent to the
recommended FIFO operation mode.
3.27 System Considerations and Guidelines
3.27.1 SRD Regulations
International regulations and national laws regulate the use of radio receivers and transmitters. Short
range devices (SRDs) for license-free operation below 1 GHz are usually operated in the 433 MHz, 868
MHz, or 915 MHz frequency bands. The CC11x1-Q1 is specifically designed for such use with its
310 MHz to 348 MHz, 420 MHz to 450 MHz, and 779 MHz to 928 MHz operating ranges. The most
important regulations when using the CC11x1-Q1 in the 433 MHz, 868 MHz, or 915 MHz frequency bands
are EN 300 220 (Europe) and FCC CFR47 Part 15 (USA). A summary of the most important aspects of
these regulations can be found in SRD Regulations for Licence Free Transceiver Operation (SWRA090).
NOTE
Compliance with regulations is dependent on complete system performance. It is the
customer's responsibility to ensure that the system complies with regulations.
3.27.2 Frequency Hopping and Multi-Channel Systems
The 433-MHz, 868-MHz, and 915-MHz bands are shared by many systems both in industrial, office, and
home environments. It is therefore recommended to use a frequency-hopping spread-spectrum (FHSS) or
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. FHSS also combats multipath
fading.
CC11x1-Q1 is highly suited for FHSS or multi-channel systems due to its agile frequency synthesizer and
effective communication interface. Using the packet handling support and data buffering is also beneficial
in such systems, as these features significantly offload the host controller.
Charge pump current, VCO current, and VCO capacitance array calibration data is required for each
frequency when implementing frequency hopping for CC11x1-Q1. There are three ways of obtaining the
calibration data from the chip:
1. Frequency hopping with calibration for each hop. The PLL calibration time is approximately 720 µs.
The blanking interval between each frequency hop is then approximately 810 µs.
2. Fast frequency hopping without calibration for each hop can be done by calibrating each frequency at
startup and saving the resulting FSCAL3, FSCAL2, and FSCAL1 register values in MCU memory.
Between each frequency hop, the calibration process can then be replaced by writing the FSCAL3,
FSCAL2, and FSCAL1 register values corresponding to the next RF frequency. The PLL turn-on time
is approximately 90 µs. The blanking interval between each frequency hop is then approximately
90 µs. The VCO current calibration result available in FSCAL2 is not dependent on the RF frequency.
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