• Ultra low-power wireless applications
operating in the 315/433/868/915 MHz
ISM/SRD bands
• Wireless alarm and security systems
• Industrial monitoring and control
Product Description
The
CC1101
transceiver designed for very low-power
wireless applications. The circuit is mainly
intended for the ISM (Industrial, Scientific and
Medical) and SRD (Short Range Device)
frequency bands at 315, 433, 868, and 915
MHz, but can easily be programmed for
operation at other frequencies in the 300-348
MHz, 387-464 MHz and 779-928 MHz bands.
CC1101
is an improved and code compatible
version of the
main improvements on the
• Improved spurious response
• Better close-in phase noise improving
• Higher input saturation level
• Improved output power ramping
• Extended frequency bands of
is a low-cost sub- 1 GHz
CC1100
Adjacent Channel Power (ACP)
performance
operation, i.e.
CC1100: 400-464 MHz and 800-928
MHz
CC1101: 387-464 MHz and 779-928
MHz
)
RF transceiver. The
CC1101
include:
• Wireless sensor networks
• AMR – Automatic Meter Reading
• Home and building automation
The RF transceiver is integrated with a highly
configurable baseband modem. The modem
supports various modulation formats and has
a configurable data rate up to 500 kBaud.
CC1101
provides extensive hardware support
for packet handling, data buffering, burst
transmissions, clear channel assessment, link
quality indication, and wake-on-radio.
The main operating parameters and the 64byte transmit/receive FIFOs of
controlled via an SPI interface. In a typical
CC1101
system, the
will be used together with a
microcontroller and a few additional passive
components.
2019181716
1
2
3
4
5
CC1101
678910
15
14
13
12
11
CC1101
can be
SWRS061B Page 1 of 93
Key Features
CC1101
RF Performance
• High sensitivity (–111 dBm at 1.2 kBaud,
868 MHz, 1% packet error rate)
• Low current consumption (14.7 mA in RX,
1.2 kBaud, 868 MHz)
• Programmable output power up to +10
dBm for all supported frequencies
• Excellent receiver selectivity and blocking
performance
• Programmable data rate from 1.2 to 500
kBaud
• Frequency bands: 300-348 MHz, 387-464
MHz and 779-928 MHz
Analog Features
•2-FSK, GFSK, and MSK supported as well
as OOK and flexible ASK shaping
• Suitable for frequency hopping systems
due to a fast settling frequency
synthesizer: 90us settling time
• Automatic Frequency Compensation
(AFC) can be used to align the frequency
synthesizer to the received center
frequency
•Integrated analog temperature sensor
Digital Features
• Flexible support for packet oriented
systems: On-chip support for sync word
detection, address check, flexible packet
length, and automatic CRC handling
• Efficient SPI interface: All registers can be
programmed with one “burst” transfer
• Digital RSSI output
• Programmable channel filter bandwidth
• Programmable Carrier Sense (CS)
indicator
• Programmable Preamble Quality Indicator
(PQI) for improved protection against false
sync word detection in random noise
• Support for automatic Clear Channel
Assessment (CCA) before transmitting (for
listen-before-talk systems)
• Support for per-package Link Quality
Indication (LQI)
• Optional automatic whitening and de-
whitening of data
Low-Power Features
• 400 nA sleep mode current consumption
• Fast startup time: 240us from sleep to RX
or TX mode (measured on EM reference
design [5] and [6])
• Wake-on-radio functionality for automatic
low-power RX polling
• Separate 64-byte RX and TX data FIFOs
(enables burst mode data transmission)
General
• Few external components: Completely on-
chip frequency synthesizer, no external
filters or RF switch needed
• Green package: RoHS compliant and no
antimony or bromine
• Small size (QLP 4x4 mm package, 20
pins)
• Suited for systems targeting compliance
with EN 300 220 (Europe) and FCC CFR
Part 15 (US).
• Support for asynchronous and
synchronous serial receive/transmit mode
for backwards compatibility with existing
radio communication protocols
SWRS061B Page 2 of 93
Abbreviations
Abbreviations used in this data sheet are described below.
ACP Adjacent Channel Power MSK Minimum Shift Keying
ADC Analog to Digital Converter N/A Not Applicable
AFC Automatic Frequency Compensation NRZ Non Return to Zero (Coding)
AGC Automatic Gain Control OOK On-Off Keying
AMR Automatic Meter Reading PA Power Amplifier
ASK Amplitude Shift Keying PCB Printed Circuit Board
BER Bit Error Rate PD Power Down
BT Bandwidth-Time product PER Packet Error Rate
CCA Clear Channel Assessment PLL Phase Locked Loop
CFR Code of Federal Regulations POR Power-On Reset
CRC Cyclic Redundancy Check PQI Preamble Quality Indicator
CS Carrier Sense PQT Preamble Quality Threshold
CW Continuous Wave (Unmodulated Carrier) PTAT Proportional To Absolute Temperature
DC Direct Current QLP Quad Leadless Package
DVGA Digital Variable Gain Amplifier QPSK Quadrature Phase Shift Keying
ESR Equivalent Series Resistance RC Resistor-Capacitor
FCC Federal Communications Commission RF Radio Frequency
FEC Forward Error Correction RSSI Received Signal Strength Indicator
FIFO First-In-First-Out RX Receive, Receive Mode
FHSS Frequency Hopping Spread Spectrum SAW Surface Aqustic Wave
2-FSK Binary Frequency Shift Keying SMD Surface Mount Device
GFSK Gaussian shaped Frequency Shift Keying SNR Signal to Noise Ratio
IF Intermediate Frequency SPI Serial Peripheral Interface
I/Q In-Phase/Quadrature SRD Short Range Devices
ISM Industrial, Scientific, Medical TBD To Be Defined
LC Inductor-Capacitor T/R Transmit/Receive
LNA Low Noise Amplifier TX Transmit, Transmit Mode
LO Local Oscillator UHF Ultra High frequency
LSB Least Significant Bit VCO Voltage Controlled Oscillator
LQI Link Quality Indicator WOR Wake on Radio, Low power polling
MCU Microcontroller Unit XOSC Crystal Oscillator
MSB Most Significant Bit XTAL Crystal
ANALOG FEATURES ........................................................................................................................................2
DIGITAL FEATURES.........................................................................................................................................2
GENERAL ............................................................................................................................................................2
TABLE OF CONTENTS.....................................................................................................................................4
1
ABSOLUTE MAXIMUM RATINGS.....................................................................................................7
18 FORWARD ERROR CORRECTION WITH INTERLEAVING.....................................................39
18.1 F
18.2 I
19 RADIO CONTROL................................................................................................................................41
19.1 P
19.2 C
19.3 V
19.4 A
19.5 W
19.6 T
19.7 RX T
20 DATA FIFO............................................................................................................................................45
21 FREQUENCY PROGRAMMING........................................................................................................47
Under no circumstances must the absolute maximum ratings given in Table 1 be violated. Stress
exceeding one or more of the limiting values may cause permanent damage to the device.
Caution! ESD sensitive device.
Precaution should be used when handling
the device in order to prevent permanent
damage.
Parameter Min Max Units Condition
Supply voltage –0.3 3.9 V All supply pins must have the same voltage
Voltage on any digital pin –0.3 VDD + 0.3
Voltage on the pins RF_P, RF_N,
and DCOUPL
Voltage ramp-up rate 120 kV/µs
Input RF level +10 dBm
Storage temperature range –50 150
Solder reflow temperature 260
ESD 750 V According to JEDEC STD 22, method A114,
ESD 400 V According to JEDEC STD 22, C101C,
V
max 3.9
–0.3 2.0 V
°C
According to IPC/JEDEC J-STD-020C
°C
Human Body Model (HBM)
Charged Device Model (CDM)
Table 1: Absolute Maximum Rati ngs
2 Operating Conditions
The operating conditions for
Parameter Min Max Unit Condition
Operating temperature -40 85
Operating supply voltage 1.8 3.6 V All supply pins must have the same voltage
CC1101
are listed Table 2 in below.
Table 2: Operating Condi tions
°C
3 General Characteristics
Parameter Min Typ Max Unit Condition/Note
Frequency range 300 348 MHz
387 464 MHz
779 928 MHz
Data rate 1.2
1.2
26
500
250
500
kBaud
kBaud
kBaud
2-FSK
GFSK, OOK, and ASK
(Shaped) MSK (also known as differential offset
QPSK)
Optional Manchester encoding (the data rate in kbps
will be half the baud rate)
Table 3: General Characteristics
SWRS061B Page 7 of 93
CC1101
4 Electrical Specifications
4.1 Current Consumption
Tc = 25°C, VDD = 3.0V if nothing else stated. All measurement results are obtained using the CC1101EM reference designs
([5] and [6]).
Reduced current settings (MDMCFG2.DEM_DCFILT_OFF=1) gives a slightly lower current consumption at the cost of a
reduction in sensitivity. See
for additional details on current consumption and sensitivity.
Parameter Min Typ Max Unit Condition
Current consumption in power
down modes
Current consumption
Current consumption,
315MHz
0.2 1
0.5
100
165
9.8
34.2
1.5
39.3
1.7 mA Only voltage regulator to digital part and crystal oscillator running
8.4 mA Only the frequency synthesizer is running (FSTXON state). This
15.4 mA Receive mode, 1.2 kBaud, reduced current, input at sensitivity
14.4 mA Receive mode, 1.2 kBaud, reduced current, input well above
15.2 mA Receive mode, 38.4 kBaud, reduced current, input at sensitivity
14.3 mA Receive mode,38.4 kBaud, reduced current, input well above
16.5 mA Receive mode, 250 kBaud, reduced current, input at sensitivity
15.1 mA Receive mode, 250 kBaud, reduced current, input well above
27.4 mA Transmit mode, +10 dBm output power
15.0 mA Transmit mode, 0 dBm output power
12.3 mA Transmit mode, –6 dBm output power
Voltage regulator to digital part off, register values retained
µA
(SLEEP state). All GDO pins programmed to 0x2F (HW to 0)
Voltage regulator to digital part off, register values retained, low-
µA
power RC oscillator running (SLEEP state with WOR enabled
Voltage regulator to digital part off, register values retained,
µA
XOSC running (SLEEP state with MCSM0.OSC_FORCE_ON set)
Voltage regulator to digital part on, all other modules in power
µA
down (XOFF state)
Automatic RX polling once each second, using low-power RC
µA
oscillator, with 460 kHz filter bandwidth and 250 kBaud data rate,
PLL calibration every 4
channel below carrier sense level (MCSM2.RX_TIME_RSSI=1).
Same as above, but with signal in channel above carrier sense
µA
level, 1.95 ms RX timeout, and no preamble/sync word found.
Automatic RX polling every 15th second, using low-power RC
µA
oscillator, with 460kHz filter bandwidth and 250 kBaud data rate,
PLL calibration every 4
channel below carrier sense level (MCSM2.RX_TIME_RSSI=1).
Same as above, but with signal in channel above carrier sense
µA
level, 29.3 ms RX timeout, and no preamble/sync word found.
(IDLE state)
currents consumption is also representative for the other
intermediate states when going from IDLE to RX or TX, including
the calibration state.
limit
sensitivity limit
limit
sensitivity limit
limit
sensitivity limit
th
wakeup. Average current with signal in
th
wakeup. Average current with signal in
SWRS061B Page 8 of 93
Parameter Min Typ Max Unit Condition
Current consumption,
433MHz
Current consumption,
868/915MHz
16.0 mA Receive mode, 1.2 kBaud, reduced current, input at sensitivity
limit
15.0 mA Receive mode, 1.2 kBaud, reduced current, input well above
sensitivity limit
15.7 mA Receive mode, 38.4 kBaud , reduced current, input at sensitivity
limit
15.0 mA Receive mode, 38.4 kBaud , reduced current, input well above
sensitivity limit
17.1 mA Receive mode, 250 kBaud, reduced current, input at sensitivity
limit
15.7 mA Receive mode, 250 kBaud, reduced current, input well above
sensitivity limit
29.2 mA Transmit mode, +10 dBm output power
16.0 mA Transmit mode, 0 dBm output power
13.1 mA Transmit mode, –6 dBm output power
15.7 mA Receive mode, 1.2 kBaud , reduced current, input at sensitivity
limit
14.7 mA Receive mode, 1.2 kBaud , reduced current, input well above
sensitivity limit
15.6 mA Receive mode, 38.4 kBaud , reduced current, input at sensitivity
limit
14.6 mA Receive mode, 38.4 kBaud , reduced current, input well above
sensitivity limit
16.9 mA Receive mode, 250 kBaud , reduced current, input at sensitivity
limit
15.6 mA Receive mode, 250 kBaud , reduced current, input well above
sensitivity limit
32.3 mA Transmit mode, +10 dBm output power
16.8 mA Transmit mode, 0 dBm output power
13.1 mA Transmit mode, –6 dBm output power
CC1101
Table 4: Electrical Specifications
SWRS061B Page 9 of 93
CC1101
4.2 RF Receive Section
Tc = 25°C, VDD = 3.0V if nothing else stated. All measurement results are obtained using the CC1101EM reference designs
([5] and [6]).
rejection
See Figure 25 for plot of selectivity versus frequency offset
Image channel
rejection,
868MHz
58 812 kHz User programmable. The bandwidth limits are proportional to
crystal frequency (given values assume a 26.0 MHz crystal).
MDMCFG2.DEM_DCFILT_OFF=1. The typical current
consumption is then reduced from 17.2 mA to 15.4 mA at
sensitivity limit. The sensitivity is typically reduced to -109 dBm
MDMCFG2.DEM_DCFILT_OFF=1. The typical current
consumption is then reduced from 18.0 mA to 16.0 mA at
sensitivity limit. The sensitivity is typically reduced to -110 dBm
MDMCFG2.DEM_DCFILT_OFF=1. The typical current
consumption is then reduced from 18.0 mA to 15.7 mA at
sensitivity limit. The sensitivity is typically reduced to -109 dBm
FIFOTHR.CLOSE_IN_RX=0
37 dB Desired channel 3 dB above the sensitivity limit. 100 kHz
channel spacing
37 dB Desired channel 3 dB above the sensitivity limit. 100 kHz
channel spacing
31 dB IF frequency 152 kHz
Desired channel 3 dB above the sensitivity limit.
20 dB Desired channel 3 dB above the sensitivity limit. 200 kHz
channel spacing
30 dB Desired channel 3 dB above the sensitivity limit. 200 kHz
channel spacing
23 dB IF frequency 152 kHz
Desired channel 3 dB above the sensitivity limit.
SWRS061B Page 10 of 93
CC1101
Parameter Min Typ Max Unit Condition/Note
868 MHz, 250 kBaud data rate, sensitivity optimized, MDMCFG2.DEM_DCFILT_OFF=0
(MSK, 1% packet error rate, 20 bytes packet length, 540 kHz digital channel filter bandwidth)
Receiver sensitivity –94 dBm Sensitivity can be traded for current consumption by setting
Saturation –17 dBm
Adjacent channel rejection 25 dB Desired channel 3 dB above the sensitivity limit. 750 kHz
Alternate channel
rejection
See Figure 26 for plot of selectivity versus frequency offset
Receiver sensitivity –94 dBm Sensitivity can be traded for current consumption by setting
915 MHz, 500 kBaud data rate, sensitivity optimized, MDMCFG2.DEM_DCFILT_OFF=0 (MDMCFG2.DEM_DCFILT_OFF=1
cannot be used for data rates > 250 kBaud)
(MSK, 1% packet error rate, 20 bytes packet length, 812 kHz digital channel filter bandwidth)
Receiver sensitivity –87 dBm
Blocking
Blocking at ±2 MHz offset,
1.2 kBaud, 868 MHz
Blocking at ±2 MHz offset,
500 kBaud, 868 MHz
Blocking at ±10 MHz
offset, 1.2 kBaud, 868
MHz
Blocking at ±10 MHz
offset, 500 kBaud, 868
MHz
40 dB Desired channel 3 dB above the sensitivity limit. 750 kHz
17 dB IF frequency 304 kHz
-50 dBm Desired channel 3dB above the sensitivity limit.
-50 dBm Desired channel 3dB above the sensitivity limit
-39 dBm Desired channel 3dB above the sensitivity limit.
-40 dBm Desired channel 3dB above the sensitivity limit.
MDMCFG2.DEM_DCFILT_OFF=1. The typical current
consumption is then reduced from 19.2 mA to 16.9 mA at
sensitivity limit. The sensitivity is typically reduced to -91 dBm
FIFOTHR.CLOSE_IN_RX=0
channel spacing
channel spacing
Desired channel 3 dB above the sensitivity limit.
MDMCFG2.DEM_DCFILT_OFF=1. The typical current
consumption is then reduced from 18.0 mA to 15.7 mA at
sensitivity limit. The sensitivity is typically reduced to -109
dBm
MDMCFG2.DEM_DCFILT_OFF=1. The typical current
consumption is then reduced from 19.2 mA to 16.9 mA at
sensitivity limit. The sensitivity is typically reduced to -91 dBm
SWRS061B Page 11 of 93
CC1101
Parameter Min Typ Max Unit Condition/Note
General
Spurious emissions -68
-66
RX latency 9 bit Serial operation. Time from start of reception until
–57
–47
dBm
dBm
25 MHz – 1 GHz
(Maximum figure is the ETSI EN 300 220 limit)
Above 1 GHz
(Maximum figure is the ETSI EN 300 220 limit)
Typical radiated spurious emission is -49 dB
measured at the VCO frequency.
data is available on the receiver data output pin is
equal to 9 bit.
Table 5: RF Receive Section
4.3 RF Transmit Section
Tc = 25°C, VDD = 3.0V, +10dBm if nothing else stated. All measurement results are obtained using the CC1101EM reference
designs([5] and [6]).
Parameter Min Typ Max Unit Condition/Note
Differential load
impedance
315 MHz
433 MHz
868/915 MHz
Output power,
highest setting
Output power,
lowest setting
Harmonics,
radiated
nd
Harm, 433 MHz
2
rd
3
Harm, 433 MHz
nd
Harm, 868 MHz
2
rd
Harm, 868 MHz
3
Harmonics,
conducted
315 MHz
433 MHz
868 MHz
915 MHz
+10 dBm Output power is programmable, and full range is available in all
-30 dBm Output power is programmable, and full range is available in all
122 + j31
116 + j41
86.5 + j43
-49
-40
-39
-64
< -35
< -53
< -43
< -45
< -39
< -33
Differential impedance as seen from the RF-port (RF_P and
RF_N) towards the antenna. Follow the CC1101EM reference
design ([5] and [6]) available from theTI website.
Ω
frequency bands
(Output power may be restricted by regulatory limits. See also
Application Note AN039 [3].
Delivered to a 50Ω single-ended load via CC1101EM reference
design ([5] and [6])RF matching network.
frequency bands.
Delivered to a 50Ω single-ended load via CC1101EM reference
design([5] and [6]) RF matching network.
Measured on CC1101EM reference designs([5] and [6])with CW,
10dBm output power
dBm
The antennas used during the radiated measurements (SMAFF433 from R.W.Badland and Nearson S331 868/915) play a part in
attenuating the harmonics
Measured with 10 dBm CW, TX frequency at 315.00 MHz,
All radiated spurious emissions are within the limits of ETSI. The
peak conducted spurious emission is -53 dBm at 699 MHz, which
is in a frequency band limited to -54 dBm by EN 300 220. An
alternative filter that can be used to reduce the emission at 699
MHz below -54 dBm, for conducted measurements, is shown in
Figure 4.
data input pin until it is observed on the RF output ports.
Table 6: RF Transmit Section
4.4 Crystal Oscillator
Tc = 25°C @ VDD = 3.0 V if nothing else is stated.
Parameter Min Typ Max Unit Condition/Note
Crystal frequency 26 26 27 MHz
Tolerance ±40 ppm This is the total tolerance including a) initial tolerance, b) crystal
ESR 100
Start-up time 150 µs Measured on the CC1101EM reference designs ([5] and [6])
loading, c) aging, and d) temperature dependence.
The acceptable crystal tolerance depends on RF frequency and
channel spacing / bandwidth.
Ω
using crystal AT-41CD2 from NDK.
This parameter is to a large degree crystal dependent.
Table 7: Crystal Oscillator Parameters
SWRS061B Page 13 of 93
CC1101
4.5 Low Power RC Oscillator
Tc = 25°C, VDD = 3.0 V if nothing else is stated. All measurement results obtained using the CC1101EM reference designs ([5]
and [6]).
Parameter Min Typ Max Unit Condition/Note
Calibrated frequency 34.7 34.7 36 kHz Calibrated RC Oscillator frequency is XTAL
Frequency accuracy after
calibration
Temperature coefficient +0.5
Supply voltage coefficient +3 % / V Frequency drift when supply voltage changes after
Initial calibration time 2 ms When the RC Oscillator is enabled, calibration is
±1 %
% / °C
frequency divided by 750
Frequency drift when temperature changes after
calibration
calibration
continuously done in the background as long as
the crystal oscillator is running.
Table 8: RC Oscillator Parameters
4.6 Frequency Synthesizer Characteristics
Tc = 25°C @ VDD = 3.0 V if nothing else is stated. All measurement results are obtained using the CC1101EM reference
designs ([5] and [6]). Min figures are given using a 27 MHz crystal. Typ and max are given using a 26 MHz crystal.
The resolution (in Hz) is equal for all frequency
bands.
(including temperature and aging) depends on
frequency band and channel bandwidth /
spacing.
Time from leaving the IDLE state until arriving in
the RX, FSTXON or TX state, when not
performing calibration.
Crystal oscillator running.
Settling time for the 1·IF frequency step from RX
to TX
Settling time for the 1·IF frequency step from TX
to RX
Calibration can be initiated manually or
automatically before entering or after leaving
RX/TX.
Table 9: Frequency Synthesizer Parameters
SWRS061B Page 14 of 93
CC1101
4.7 Analog Temperature Sensor
The characteristics of the analog temperature sensor at 3.0 V supply voltage are listed in Table 10
below. Note that it is necessary to write 0xBF to the PTEST register to use the analog temperature
sensor in the IDLE state.
Parameter Min Typ Max Unit Condition/Note
Output voltage at –40°C
Output voltage at 0°C
Output voltage at +40°C
Output voltage at +80°C
Temperature coefficient 2.45
Error in calculated
temperature, calibrated
Current consumption
increase when enabled
0.651 V
0.747 V
0.847 V
0.945 V
mV/°C Fitted from –20 °C to +80 °C
*
-2
0 2
0.3 mA
*
°C From –20 °C to +80 °C when using 2.45 mV / °C, after
1-point calibration at room temperature
*
The indicated minimum and maximum error with 1point calibration is based on simulated values for
typical process parameters
Table 10: Analog Temperature Sensor Parameters
4.8 DC Characteristics
Tc = 25°C if nothing else stated.
Digital Inputs/Outputs Min Max Unit Condition
Logic "0" input voltage 0 0.7 V
Logic "1" input voltage VDD-0.7 VDD V
Logic "0" output voltage 0 0.5 V For up to 4 mA output current
Logic "1" output voltage VDD-0.3 VDD V For up to 4 mA output current
Logic "0" input current N/A –50 nA Input equals 0V
Logic "1" input current N/A 50 nA Input equals VDD
Table 11: DC Characteristics
4.9 Power-On Reset
When the power supply complies with the requirements in Table 12 below, proper Power-On-Reset
functionality is guaranteed. Otherwise, the chip should be assumed to have unknown state until
transmitting an SRES strobe over the SPI interface. See Section 19.1 on page 41 for further details.
Parameter Min Typ Max Unit Condition/Note
Power-up ramp-up time. 5 ms From 0V until reaching 1.8V
Power off time 1 ms Minimum time between power-on and power-off
Table 12: Power-On Reset Requirements
SWRS061B Page 15 of 93
5 Pin Configuration
GND
RBIAS
DGUARD
GND
SI
20 19 18 17 16
CC1101
SCLK
SO (GDO1)
GDO2
DVDD
DCOUPL
1
2
3
4
5
GDO0 (ATEST)
XOSC_Q1
AVDD
CSn
15
AVDD
14
AVDD
13
RF_N
12
RF_P
AVDD
11
XOSC_Q2
GND
Exposed die
attach pad
109876
Figure 1: Pinout Top View
Note: The exposed die attach pad must be connected to a solid ground plane as this is the main
ground connection for the chip.
Pin # Pin Name Pin type Description
1 SCLK Digital Input Serial configuration interface, clock input
2 SO (GDO1) Digital Output Serial configuration interface, data output.
Optional general output pin when CSn is high
3 GDO2 Digital Output Digital output pin for general use:
• Test signals
• FIFO status signals
• Clear Channel Indicator
• Clock output, down-divided from XOSC
• Serial output RX data
4 DVDD Power (Digital) 1.8 - 3.6 V digital power supply for digital I/O’s and for the digital core
5 DCOUPL Power (Digital) 1.6 - 2.0 V digital power supply output for decoupling.
6 GDO0
(ATEST)
7 CSn Digital Input Serial configuration interface, chip select
8 XOSC_Q1 Analog I/O Crystal oscillator pin 1, or external clock input
9 AVDD Power (Analog) 1.8 - 3.6 V analog power supply connection
Digital I/O
voltage regulator
NOTE: This pin is intended for use with the
to provide supply voltage to other devices.
Digital output pin for general use:
• Test signals
• FIFO status signals
• Clear Channel Indicator
• Clock output, down-divided from XOSC
• Serial output RX data
• Serial input TX data
Also used as analog test I/O for prototype/production testing
CC1101
only. It can not be used
SWRS061B Page 16 of 93
Pin # Pin Name Pin type Description
10 XOSC_Q2 Analog I/O Crystal oscillator pin 2
11 AVDD Power (Analog) 1.8 -3.6 V analog power supply connection
12 RF_P RF I/O Positive RF input signal to LNA in receive mode
Positive RF output signal from PA in transmit mode
13 RF_N RF I/O Negative RF input signal to LNA in receive mode
Negative RF output signal from PA in transmit mode
14 AVDD Power (Analog) 1.8 - 3.6 V analog power supply connection
15 AVDD Power (Analog) 1.8 - 3.6 V analog power supply connection
16 GND Ground (Analog) Analog ground connection
17 RBIAS Analog I/O External bias resistor for reference current
18 DGUARD Power (Digital) Power supply connection for digital noise isolation
19 GND Ground (Digital) Ground connection for digital noise isolation
20 SI Digital Input Serial configuration interface, data input
Table 13: Pinout Overview
CC1101
6 Circuit Description
RADIO CONTROL
ADC
LNA
ADC
RF_P
RF_N
PA
RC OSC
Figure 2:
0
90
BIAS
RBIAS XOSC_Q1 XOSC_ Q2
CC1101
A simplified block diagram of
CC1101
is shown
in Figure 2.
CC1101
features a low-IF receiver. The received
RF signal is amplified by the low-noise
amplifier (LNA) and down-converted in
quadrature (I and Q) to the intermediate
frequency (IF). At IF, the I/Q signals are
digitised by the ADCs. Automatic gain control
(AGC), fine channel filtering and demodulation
bit/packet synchronization are performed
digitally.
The transmitter part of
CC1101
is based on
direct synthesis of the RF frequency. The
FREQ
SYNTH
XOSC
Simplified Block Dia gram
RXFIFO
DEMODULATOR
PACKET HANDLER
FEC / INTERLEAVER
MODULATOR
TXFIFO
DIGITAL INTERFACE TO MCU
SCLK
SO (GDO1)
SI
CSn
GDO0 (ATEST)
GDO2
frequency synthesizer includes a completely
on-chip LC VCO and a 90 degree phase
shifter for generating the I and Q LO signals to
the down-conversion mixers in receive mode.
A crystal is to be connected to XOSC_Q1 and
XOSC_Q2. The crystal oscillator generates the
reference frequency for the synthesizer, as
well as clocks for the ADC and the digital part.
A 4-wire SPI serial interface is used for
configuration and data buffer access.
The digital baseband includes support for
channel configuration, packet handling, and
data buffering.
SWRS061B Page 17 of 93
7 Application Circuit
CC1101
Only a few external components are required
CC1101
for using the
. The recommended
application circuits are shown in Figure 3 and
Figure 4. The external components are
described in Table 14, and typical values are
given in Table 15.
Bias Resistor
The bias resistor R171 is used to set an
accurate bias current.
Balun and RF Matching
The components between the RF_N/RF_P
pins and the point where the two signals are
joined together (C131, C121, L121 and L131
for the 315/433 MHz reference design [5].
L121, L131, C121, L122, C131, C122 and
L132 for the 868/915 MHz reference design
[6]) form a balun that converts the differential
RF signal on
CC1101
to a single-ended RF
signal. C124 is needed for DC blocking.
Together with an appropriate LC network, the
balun components also transform the
impedance to match a 50 Ω antenna (or
cable). Suggested values for 315 MHz, 433
MHz, and 868/915 MHz are listed in Table 15.
The balun and LC filter component values and
their placement are important to keep the
performance optimized. It is highly
recommended to follow the CC1101EM
reference design [5] and [6].
Crystal
The crystal oscillator uses an external crystal
with two loading capacitors (C81 and C101).
See Section 27 on page 52 for details.
Additional Filtering
Additional external components (e.g. an RF
SAW filter) may be used in order to improve
the performance in specific applications.
Power Supply Decoupling
The power supply must be properly decoupled
close to the supply pins. Note that decoupling
capacitors are not shown in the application
circuit. The placement and the size of the
decoupling capacitors are very important to
achieve the optimum performance. The
CC1101EM reference design ([5] and [6])
should be followed closely.
Component Description
C51 Decoupling capacitor for on-chip voltage regulator to digital part
C81/C101 Crystal loading capacitors, see Section 27 on page 52 for details
Component Value at 315MHz Value at 433MHz Value at
C51 100 nF ± 10%, 0402 X5R Murata GRM1555C series
C81 27 pF ± 5%, 0402 NP0 Murata GRM1555C series
C101 27 pF ± 5%, 0402 NP0 Murata GRM1555C series
C121 6.8 pF ± 0.5 pF,
0402 NP0
C122 12 pF ± 5%, 0402
NP0
C123 6.8 pF ± 0.5 pF,
0402 NP0
C124 220 pF ± 5%,
0402 NP0
C125 220 pF ± 5%,
0402 NP0
C126 2.2 pF ± 0.25%,
C127 2.2 pF ± 0.25%,
C131 6.8 pF ± 0.5 pF,
0402 NP0
L121 33 nH ± 5%, 0402
monolithic
L122 18 nH ± 5%, 0402
monolithic
L123 33 nH ± 5%, 0402
monolithic
L124 12 nH ± 5%, 0402
L125 9.1 nH ± 5%, 0402
L131 33 nH ± 5%, 0402
monolithic
L132 18 nH ± 5%, 0402
R171 56 kΩ ± 1%, 0402 Koa RK73 series
XTAL 26.0 MHz surface mount crystal NDK, AT-41CD2
3.9 pF ± 0.25 pF,
0402 NP0
8.2 pF ± 0.5 pF,
0402 NP0
5.6 pF ± 0.5 pF,
0402 NP0
220 pF ± 5%,
0402 NP0
220 pF ± 5%,
0402 NP0
3.9 pF ± 0.25 pF,
0402 NP0
27 nH ± 5%, 0402
monolithic
22 nH ± 5%, 0402
monolithic
27 nH ± 5%, 0402
monolithic
27 nH ± 5%, 0402
monolithic
868/915MHz
1.0 pF ± 0.25 pF,
0402 NP0
1.5 pF ± 0.25 pF,
0402 NP0
3.3 pF ± 0.25 pF,
0402 NP0
100 pF ± 5%, 0402
NP0
100 pF ± 5%, 0402
NP0
0402 NP0
0402 NP0
1.5 pF ± 0.25 pF,
0402 NP0
12 nH ± 5%, 0402
monolithic
18 nH ± 5%, 0402
monolithic
12 nH ± 5%, 0402
monolithic
monolithic
monolithic
12 nH ± 5%, 0402
monolithic
monolithic
Manufacturer
Murata GRM1555C series
Murata GRM1555C series
Murata GRM1555C series
Murata GRM1555C series
Murata GRM1555C series
Murata GRM1555C series
Murata GRM1555C series
Murata GRM1555C series
Murata LQG15HS series
Murata LQG15HS series
Murata LQG15HS series
Murata LQG15HS series
Murata LQG15HS series
Murata LQG15HS series
Murata LQG15HS series
Table 15: Bill Of Materials for the Application Circuit
The Gerber files for the CC1101EM reference designs ([5] and [6]) are available from the TI website.
SWRS061B Page 20 of 93
8 Configuration Overview
CC1101
CC1101
can be configured to achieve optimum
performance for many different applications.
Configuration is done using the SPI interface.
The following key parameters can be
programmed:
• Power-down / power up mode
• Crystal oscillator power-up / power-down
• Receive / transmit mode
• RF channel selection
• Data rate
• Modulation format
• RX channel filter bandwidth
• RF output power
• Data buffering with separate 64-byte
receive and transmit FIFOs
• Packet radio hardware support
• Forward Error Correction (FEC) with
interleaving
• Data Whitening
• Wake-On-Radio (WOR)
Details of each configuration register can be
found in Section 33, starting on page 59.
Figure 5 shows a simplified state diagram that
explains the main
typical usage and current consumption. For
detailed information on controlling the
state machine, and a complete state diagram,
see Section 19, starting on page 41.
CC1101
states, together with
CC1101
SWRS061B Page 21 of 93
s
CC1101
Default state when the radio is not
receiving or transmitting. Typ.
current consumption: 1.7 mA.
Used for calibrating frequency
synthesizer upfront (entering
receive or transmit mode can
then be done quicker).
Transitional state. Typ. current
consumption: 8.4 mA.
Frequency synthesizer is on,
ready to start transmitting.
Transmission starts very
quickly after receiving the STX
command strobe.Typ. current
consumption: 8.4 mA.
Typ. current consumption:
13.1 mA at -6 dBm output,
16.8 mA at 0 dBm output,
32.8 mA at +10 dBm output.
SPWD or wake-on-radio (WOR)
SIDLE
IDLE
SCAL
Manual freq.
synth. calibration
Frequency
synthesizer on
STX
TXOFF_MODE = 01
Transmit modeReceive mode
SRX or STX or SFSTXON or wake-on-radio (WOR)
Frequency
synthesizer startup,
SFSTXON
optional calibration,
settling
STX
SFSTXON or RXOFF_MODE = 01
STX or RXOFF_MODE=10
SRX or TXOFF_M ODE = 11
CSn = 0
SXOFF
CSn = 0
Frequency synthesizer is turned on, can optionally be
calibrated, and then settles to the correct frequency.
Transitional state. Typ. current consumption: 8.4 mA.
SRX or wake-on-radio (WOR)
Sleep
Crystal
oscillator off
Lowest power mode. Most
register values are retained.
Current consumption typ
400 nA, or typ 900 nA when
wake-on-radio (WOR) is
enabled.
All register values are
retained. Typ. current
consumption; 165 µA.
Typ. current
consumption:
from 14.7 mA (strong
input signal) to 15.7 mA
(weak input signal).
In FIFO-based modes,
transmission is turned off and
this state entered if the TX
FIFO becomes empty in the
middle of a packet. Typ.
current consumption: 1.7 mA.
TXOFF_MODE = 00
TX FIFO
underflow
SFTX
Optional transitional state. Typ.
current consumption: 8.4 mA.
Optional freq.
synth. calibration
IDLE
RXOFF_MODE = 00
SFRX
RX FIFO
overflow
In FIFO-based modes,
reception is turned off and thi
state entered if the RX FIFO
overflows. Typ. current
consumption: 1.7 mA.
Figure 5:Simplified State Diagram, with Typical Current Consumption at 1.2 kBaud Data Rate
and MDMCFG2.DEM_DCFILT_OFF=1 (current optimized). Freq. Band = 868 MHz
SWRS061B Page 22 of 93
9 Configuration Software
CC1101
CC1101
can be configured using the SmartRF®
Studio software [7]. The SmartRF
software is highly recommended for obtaining
optimum register settings, and for evaluating
performance and functionality. A screenshot of
the SmartRF
is shown in Figure 6.
®
Studio user interface for
®
Studio
CC1101
After chip reset, all the registers have default
values as shown in the tables in Section 33.
The optimum register setting might differ from
the default value. After a reset all registers that
shall be different from the default value
therefore needs to be programmed through
the SPI interface.
Figure 6: SmartRF
®
Studio [7] User Interface
10 4-wire Serial Configuration and Data Interface
CC1101
compatible interface (SI, SO, SCLK and CSn)
where
also used to read and write buffered data. All
transfers on the SPI interface are done most
significant bit first.
All transactions on the SPI interface start with
a header byte containing a R/W¯ bit, a burst
access bit (B), and a 6-bit address (A
is configured via a simple 4-wire SPI-
CC1101
is the slave. This interface is
– A0).
5
SWRS061B Page 23 of 93
The CSn pin must be kept low during transfers
on the SPI bus. If CSn goes high during the
transfer of a header byte or during read/write
from/to a register, the transfer will be
cancelled. The timing for the address and data
transfer on the SPI interface is shown in Figure
7 with reference to Table 16.
When CSn is pulled low, the MCU must wait
until
CC1101
SO pin goes low before starting to
CC1101
transfer the header byte. This indicates that
the crystal is running. Unless the chip was in
always go low immediately after taking CSn
low.
the SLEEP or XOFF states, the SO pin will
Figure 7: Configuration Registers Write and Read Operations
Parameter Description Min Max Units
f
SCLK
SCLK frequency
100 ns delay inserted between address byte and data byte (single access), or
between address and data, and between each data byte (burst access).
SCLK frequency, single access
No delay between address and data byte
- 10
- 9
MHz
SCLK frequency, burst access
No delay between address and data byte, or between data bytes
t
CSn low to positive edge on SCLK, in power-down mode 150 -
sp,pd
tsp CSn low to positive edge on SCLK, in active mode 20 - ns
tch Clock high 50 - ns
tcl Clock low 50 - ns
t
Clock rise time - 5 ns
rise
t
Clock fall time - 5 ns
fall
tsd Setup data (negative SCLK edge) to
thd Hold data after positive edge on SCLK 20 - ns
tns Negative edge on SCLK to CSn high. 20 - ns
positive edge on SCLK
(tsd applies between address and data bytes, and between
data bytes)
Single access
Burst access
- 6.5
µs
55
76
-
-
ns
Table 16: SPI Interface Timing Requirements
Note: The minimum t
figure in Table 16 can be used in cases where the user does not read the
sp,pd
CHIP_RDYn signal. CSn low to positive edge on SCLK when the chip is woken from power-down
depends on the start-up time of the crystal being used. The 150 us in Table 16 is the crystal oscillator
start-up time measured on CC1101EM reference designs ([5] and [6]) using crystal AT-41CD2 from
NDK.
SWRS061B Page 24 of 93
CC1101
10.1 Chip Status Byte
When the header byte, data byte, or command
strobe is sent on the SPI interface, the chip
status byte is sent by the
CC1101
on the SO pin.
The status byte contains key status signals,
useful for the MCU. The first bit, s7, is the
CHIP_RDYn signal; this signal must go low
before the first positive edge of SCLK. The
CHIP_RDYn signal indicates that the crystal is
running.
Bits 6, 5, and 4 comprise the STATE value.
This value reflects the state of the chip. The
XOSC and power to the digital core is on in
the IDLE state, but all other modules are in
power down. The frequency and channel
configuration should only be updated when the
chip is in this state. The RX state will be active
when the chip is in receive mode. Likewise, TX
is active when the chip is transmitting.
The last four bits (3:0) in the status byte contains FIFO_BYTES_AVAILABLE. For read
operations (the R/W¯ bit in the header byte is
set to 1), the FIFO_BYTES_AVAILABLE field
contains the number of bytes available for
reading from the RX FIFO. For write
operations (the R/W¯ bit in the header byte is
set to 0), the FIFO_BYTES_AVAILABLE field
contains the number of bytes that can be
written to the TX FIFO. When
FIFO_BYTES_AVAILABLE=15, 15 or more
bytes are available/free.
Table 17 gives a status byte summary.
Bits Name Description
7 CHIP_RDYn Stays high until power and crystal have stabilized. Should always be low when using
6:4 STATE[2:0] Indicates the current main state machine mode
3:0 FIFO_BYTES_AVAILABLE[3:0] The number of bytes available in the RX FIFO or free bytes in the TX FIFO
the SPI interface.
Value State Description
000 IDLE IDLE state
001 RX Receive mode
010 TX Transmit mode
011 FSTXON Fast TX ready
100 CALIBRATE Frequency synthesizer calibration is running
101 SETTLING PLL is settling
110 RXFIFO_OVERFLOW RX FIFO has overflowed. Read out any
111 TXFIFO_UNDERFLOW TX FIFO has underflowed. Acknowledge with
(Also reported for some transitional states instead
of SETTLING or CALIBRATE)
useful data, then flush the FIFO with SFRX
SFTX
Table 17: Status Byte Summary
10.2 Register Access
CC1101
The configuration registers on the
are
located on SPI addresses from 0x00 to 0x2E.
Table 35 on page 60 lists all configuration
registers. It is highly recommended to use
SmartRF
®
Studio [7] to generate optimum
register settings. The detailed description of
each register is found in Section 33.1 and
33.2, starting on page 63. All configuration
registers can be both written to and read. The
R/W¯ bit controls if the register should be
SWRS061B Page 25 of 93
written to or read. When writing to registers,
the status byte is sent on the SO pin each time
a header byte or data byte is transmitted on
the SI pin. When reading from registers, the
status byte is sent on the SO pin each time a
header byte is transmitted on the SI pin.
Registers with consecutive addresses can be
accessed in an efficient way by setting the
burst bit (B) in the header byte. The address
bits (A
– A0) set the start address in an
5
internal address counter. This counter is
CC1101
incremented by one each new byte (every 8
clock pulses). The burst access is either a
read or a write access and must be terminated
by setting CSn high.
For register addresses in the range 0x300x3D, the burst bit is used to select between
status registers, burst bit is one, and command
strobes, burst bit is zero (see 10.4 below).
Because of this, burst access is not available
for status registers and they must be accesses
one at a time. The status registers can only be
read.
10.3 SPI Read
When reading register fields over the SPI
interface while the register fields are updated
by the radio hardware (e.g. MARCSTATE or
TXBYTES), there is a small, but finite,
probability that a single read from the register
is being corrupt. As an example, the
probability of any single read from TXBYTES
being corrupt, assuming the maximum data
rate is used, is approximately 80 ppm. Refer to
the
CC1101
10.4 Command Strobes
Command Strobes may be viewed as single
byte instructions to
command strobe register, internal sequences
will be started. These commands are used to
disable the crystal oscillator, enable receive
mode, enable wake-on-radio etc. The 13
command strobes are listed in Table 34 on
page 59.
The command strobe registers are accessed
by transferring a single header byte (no data is
being transferred). That is, only the R/W¯ bit,
the burst access bit (set to 0), and the six
address bits (in the range 0x30 through 0x3D)
are written. The R/W¯ bit can be either one or
zero and will determine how the
FIFO_BYTES_AVAILABLE field in the status
byte should be interpreted.
When writing command strobes, the status
byte is sent on the SO pin.
Errata Notes [1] for more details.
CC1101
. By addressing a
the SPWD and the SXOFF strobes that are
executed when CSn goes high.
Figure 8: SRES Command Strobe
10.5 FIFO Access
The 64-byte TX FIFO and the 64-byte RX
FIFO are accessed through the 0x3F address.
When the R/W¯ bit is zero, the TX FIFO is
accessed, and the RX FIFO is accessed when
the R/W¯ bit is one.
The TX FIFO is write-only, while the RX FIFO
is read-only.
The burst bit is used to determine if the FIFO
access is a single byte access or a burst
access. The single byte access method
expects a header byte with the burst bit set to
zero and one data byte. After the data byte a
new header byte is expected; hence, CSn can
remain low. The burst access method expects
one header byte and then consecutive data
bytes until terminating the access by setting
CSn high.
The following header bytes access the FIFOs:
• 0x3F: Single byte access to TX FIFO
• 0x7F: Burst access to TX FIFO
• 0xBF: Single byte access to RX FIFO
• 0xFF: Burst access to RX FIFO
When writing to the TX FIFO, the status byte
(see Section 10.1) is output for each new data
byte on SO, as shown in Figure 7. This status
byte can be used to detect TX FIFO underflow
while writing data to the TX FIFO. Note that
the status byte contains the number of bytes
free before writing the byte in progress to the
TX FIFO. When the last byte that fits in the TX
FIFO is transmitted on SI, the status byte
received concurrently on SO will indicate that
one byte is free in the TX FIFO.
A command strobe may be followed by any
other SPI access without pulling CSn high.
However, if an SRES strobe is being issued,
one will have to waith for SO to go low again
before the next header byte can be issued as
shown in Figure 8. The command strobes are
executed immediately, with the exception of
SWRS061B Page 26 of 93
The TX FIFO may be flushed by issuing a
SFTX command strobe. Similarly, a SFRX
command strobe will flush the RX FIFO. A
SFTX or SFRX command strobe can only be
issued in the IDLE, TXFIFO_UNDERLOW, or
RXFIFO_OVERFLOW states. Both FIFOs are
flushed when going to the SLEEP state.
CC1101
Figure 9 gives a brief overview of different
register access types possible.
10.6 PATABLE Access
The 0x3E address is used to access the
PATABLE, which is used for selecting PA
power control settings. The SPI expects up to
eight data bytes after receiving the address.
By programming the PATABLE, controlled PA
power ramp-up and ramp-down can be
achieved, as well as ASK modulation shaping
for reduced bandwidth. See SmartRF
[7] for recommended shaping / PA ramping
sequences.
See Section 24 on page 48 for details on
output power programming.
The PATABLE is an 8-byte table that defines
the PA control settings to use for each of the
eight PA power values (selected by the 3-bit
value FREND0.PA_POWER). The table is
®
Studio
written and read from the lowest setting (0) to
the highest (7), one byte at a time. An index
counter is used to control the access to the
table. This counter is incremented each time a
byte is read or written to the table, and set to
the lowest index when CSn is high. When the
highest value is reached the counter restarts
at zero.
The access to the PATABLE is either single
byte or burst access depending on the burst
bit. When using burst access the index counter
will count up; when reaching 7 the counter will
restart at 0. The R/W¯ bit controls whether the
access is a read or a write access.
If one byte is written to the PATABLE and this
value is to be read out then CSn must be set
high before the read access in order to set the
index counter back to zero.
Note that the content of the PATABLE is lost
when entering the SLEEP state, except for the
first byte (index 0).
Figure 9: Register Access Types
11 Microcontroller Interface and Pin Configuration
In a typical system,
microcontroller. This microcontroller must be
able to:
• Program
• Read and write buffered data
• Read back status information via the 4-wire
SPI-bus configuration interface (SI, SO,
SCLK and CSn).
11.1 Configuration Interface
The microcontroller uses four I/O pins for the
SPI configuration interface (SI, SO, SCLK and
CSn). The SPI is described in Section 10 on
page 23.
CC1101
CC1101
will interface to a
into different modes
11.2 General Control and Status Pins
CC1101
The
pins (GDO0 and GDO2) and one shared pin
(GDO1) that can output internal status
information useful for control software. These
pins can be used to generate interrupts on the
MCU. See Section 30 page 54 for more details
on the signals that can be programmed.
GDO1 is shared with the SO pin in the SPI
interface. The default setting for GDO1/SO is
3-state output. By selecting any other of the
programming options, the GDO1/SO pin will
become a generic pin. When CSn is low, the
pin will always function as a normal SO pin.
In the synchronous and asynchronous serial
modes, the GDO0 pin is used as a serial TX
data input pin while in transmit mode.
The GDO0 pin can also be used for an on-chip
analog temperature sensor. By measuring the
has two dedicated configurable
SWRS061B Page 27 of 93
CC1101
voltage on the GDO0 pin with an external
ADC, the temperature can be calculated.
Specifications for the temperature sensor are
found in Section 4.7 on page 15.
With default PTEST register setting (0x7F) the
temperature sensor output is only available
when the frequency synthesizer is enabled
(e.g. the MANCAL, FSTXON, RX, and TX
states). It is necessary to write 0xBF to the
PTEST register to use the analog temperature
sensor in the IDLE state. Before leaving the
IDLE state, the PTEST register should be
restored to its default value (0x7F).
11.3 Optional Radio Control Feature
The
CC1101
has an optional way of controlling
the radio, by reusing SI, SCLK, and CSn from
the SPI interface. This feature allows for a
simple three-pin control of the major states of
the radio: SLEEP, IDLE, RX, and TX.
This optional functionality is enabled with the
MCSM0.PIN_CTRL_EN configuration bit.
State changes are commanded as follows:
When CSn is high the SI and SCLK is set to
the desired state according to Table 18. When
CSn goes low the state of SI and SCLK is
latched and a command strobe is generated
internally according to the pin configuration. It
is only possible to change state with this
functionality. That means that for instance RX
will not be restarted if SI and SCLK are set to
RX and CSn toggles. When CSn is low the SI
and SCLK has normal SPI functionality.
All pin control command strobes are executed
immediately, except the SPWD strobe, which is
delayed until CSn goes high.
CSn SCLK SI Function
1 X X
0 0 Generates SPWD strobe
↓
0 1 Generates STX strobe
↓
1 0 Generates SIDLE strobe
↓
1 1 Generates SRX strobe
↓
SPI
0
mode
SPI
mode
Chip unaffected by SCLK/
SPI mode (wakes up into
IDLE if in SLEEP/XOFF)
SI
Table 18: Optional Pin Control Coding
12 Data Rate Programming
The data rate used when transmitting, or the
data rate expected in receive is programmed
by the MDMCFG3.DRATE_M and the
MDMCFG4.DRATE_E configuration registers.
The data rate is given by the formula below.
As the formula shows, the programmed data
rate depends on the crystal frequency.
_
R⋅
()
=
DATA
2
2_256
MDRATE
⋅+
28
The following approach can be used to find
suitable values for a given data rate:
⎢
⎛
R
DATA
⎜
log_
=
EDRATE
⎢
2
⎜
R
⎝
DATA
⋅
f
XOSC
2
⋅
2
⎢
⎣
_
=
MDRATE
f
XOSC
EDRATE
f
XOSC
20
⎥
⎞
2
⋅
⎟
⎥
⎟
⎥
⎠
⎦
−
256
28
_
EDRATE
If DRATE_M is rounded to the nearest integer
and becomes 256, increment DRATE_E and
use DRATE_M = 0.
The data rate can be set from 1.2 kBaud to
500 kBaud with the minimum step size of:
Min Data
Rate
[kBaud]
0.8 1.2 / 2.4 3.17 0.0062
3.17 4.8 6.35 0.0124
6.35 9.6 12.7 0.0248
12.7 19.6 25.4 0.0496
25.4 38.4 50.8 0.0992
50.8 76.8 101.6 0.1984
101.6 153.6 203.1 0.3967
203.1 250 406.3 0.7935
406.3 500 500 1.5869
Typical Data
Rate
[kBaud]
Max Data
Rate
[kBaud]
Data rate
Step Size
[kBaud]
Table 19: Data Rate Step Size
SWRS061B Page 28 of 93
13 Receiver Channel Filter Bandwidth
CC1101
In order to meet different channel width
requirements, the receiver channel filter is
programmable. The MDMCFG4.CHANBW_E and
MDMCFG4.CHANBW_M configuration registers
control the receiver channel filter bandwidth,
which scales with the crystal oscillator
frequency. The following formula gives the
relation between the register settings and the
channel filter bandwidth:
For best performance, the channel filter
bandwidth should be selected so that the
signal bandwidth occupies at most 80% of the
channel filter bandwidth. The channel centre
tolerance due to crystal accuracy should also
be subtracted from the signal bandwidth. The
following example illustrates this:
With the channel filter bandwidth set to
500 kHz, the signal should stay within 80% of
500 kHz, which is 400 kHz. Assuming
915 MHz frequency and ±20 ppm frequency
uncertainty for both the transmitting device and
the receiving device, the total frequency
uncertainty is ±40 ppm of 915MHz, which is
±37 kHz. If the whole transmitted signal
bandwidth is to be received within 400kHz, the
transmitted signal bandwidth should be
maximum 400kHz – 2·37 kHz, which is
326 kHz.
14 Demodulator, Symbol Synchronizer, and Data Decision
CC1101
contains an advanced and highly
configurable demodulator. Channel filtering
and frequency offset compensation is
performed digitally. To generate the RSSI level
(see Section 17.3 for more information) the
signal level in the channel is estimated. Data
filtering is also included for enhanced
performance.
14.1 Frequency Offset Compensation
When using 2-FSK, GFSK, or MSK
modulation, the demodulator will compensate
for the offset between the transmitter and
receiver frequency, within certain limits, by
estimating the centre of the received data.
This value is available in the FREQEST status
register. Writing the value from FREQEST into FSCTRL0.FREQOFF the frequency
synthesizer is automatically adjusted
according to the estimated frequency offset.
The tracking range of the algorithm is
selectable as fractions of the channel
bandwidth with the FOCCFG.FOC_LIMIT
configuration register.
If the FOCCFG.FOC_BS_CS_GATE bit is set,
the offset compensator will freeze until carrier
sense asserts. This may be useful when the
radio is in RX for long periods with no traffic,
since the algorithm may drift to the boundaries
when trying to track noise.
The tracking loop has two gain factors, which
affects the settling time and noise sensitivity of
the algorithm. FOCCFG.FOC_PRE_K sets the
gain before the sync word is detected, and
FOCCFG.FOC_POST_K selects the gain after
the sync word has been found.
Note that frequency offset compensation is not
supported for ASK or OOK modulation.
14.2 Bit Synchronization
The bit synchronization algorithm extracts the
clock from the incoming symbols. The
algorithm requires that the expected data rate
is programmed as described in Section 12 on
page 28. Re-synchronization is performed
continuously to adjust for error in the incoming
symbol rate.
SWRS061B Page 29 of 93
Loading...
+ 65 hidden pages
You need points to download manuals.
1 point = 1 manual.
You can buy points or you can get point for every manual you upload.