TI CC2400 2.4 ghz low-power rf transceiver Datasheet

CC2400
CC2400
2.4 GHz Low-Power RF Transceiver
Applications
• 2.4 GHz MHz ISM/SRD band systems
• Game controllers
• Sports and leisure equipment
• Wireless audio
• PC peripherals
• Advanced toys
Product Description
The CC2400 is a true single-chip 2.4 GHz
RF transceiver designed for low-power
and low-voltage wireless applications. The
RF transceiver is integrated with a
baseband modem supporting data rates
up to 1 Mbps.
The CC2400 is a low-cost, highly integrated
solution
enabling
robust
wireless
communication in the 2.4 - 2.4835 GHz
unlicensed ISM band. It is intended for
systems compliant with world-wide
regulations covered by EN 300 440
(Europe), CFR47 Part 15 (US) and ARIB
STD-T66 (Japan).
and error detection reducing the workload
on the host microcontroller.
The main operating parameters of CC2400
can be programmed via an SPI-bus. In a
typical system CC2400 will be used
together with a microcontroller and a few
external, passive components.
CC2400 is based on Chipcon’s SmartRF03 technology in 0.18 µm CMOS.
Targeting a wide range of applications at
2.4 GHz, the CC2400 supports over-the-air
data rates of 10 kbps, 250 kbps and
1 Mbps without requiring any modifications
to the hardware.
The CC2400 provides extensive hardware
support for packet handling, data
buffering, burst transmissions, data coding
Key Features
• True single-chip 2.4 GHz RF
transceiver with baseband modem
• 10 kbps, 250 kbps and 1 Mbps overthe-air data rates
• Low current consumption (RX: 24 mA)
• Low core supply voltage (1.8 V)
• Programmable output power
• No external RF switch / filter needed
• I/Q low-IF receiver
• I/Q direct up-conversion transmitter
• Few external components
• FIFO allows bursting of data
•
•
•
•
•
Packet handling hardware
Data buffering
Digital RSSI output
Small size (QFN 48 package), 7x7 mm
Reference design complies with EN
300 328, EN 300 440, FCC CFR47 part
15 and ARIB STD-T66
• Powerful and flexible development
tools available
• Easy-to-use software for generating
the CC2400 configuration data
This document contains information on a pre-production product. Specifications and information herein are subject to
change without notice.
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CC2400
Table of contents
1 ABBREVIATIONS.............................................................................................................. 4
2 FEATURES ........................................................................................................................ 5
3 ABSOLUTE MAXIMUM RATINGS.................................................................................... 6
4 OPERATING CONDITIONS .............................................................................................. 6
5 ELECTRICAL SPECIFICATIONS ..................................................................................... 7
6 GENERAL CHARACTERISTICS ...................................................................................... 7
7 RF TRANSMIT SECTION .................................................................................................. 8
8 RF RECEIVE SECTION..................................................................................................... 9
9 AFC SECTION ................................................................................................................. 10
10
RSSI / CARRIER SENSE SECTION............................................................................ 11
11
IF SECTION.................................................................................................................. 11
12
FREQUENCY SYNTHESIZER SECTION.................................................................... 11
13
DIGITAL INPUTS/OUTPUTS....................................................................................... 12
14
PIN ASSIGNMENT....................................................................................................... 13
15
CIRCUIT DESCRIPTION ............................................................................................. 15
16
APPLICATION CIRCUIT.............................................................................................. 17
16.1
INPUT / OUTPUT MATCHING ....................................................................................... 17
16.2
BIAS RESISTOR ........................................................................................................ 17
16.3
CRYSTAL ................................................................................................................. 17
16.4
DIGITAL I/O ............................................................................................................. 17
16.5
POWER SUPPLY DECOUPLING AND FILTERING ............................................................ 17
16.6
POWER SUPPLY SWITCHING ...................................................................................... 17
17
CONFIGURATION OVERVIEW................................................................................... 20
18
CONFIGURATION SOFTWARE.................................................................................. 20
19
4-WIRE SERIAL CONFIGURATION INTERFACE...................................................... 21
20
OVERVIEW OF CONFIGURATIONS AND HARDWARE SUPPORT ........................ 24
21
MICROCONTROLLER INTERFACE AND PIN CONFIGURATION ........................... 25
21.1
CONFIGURATION INTERFACE ..................................................................................... 25
21.2
SIGNAL INTERFACE IN UN-BUFFERED MODE................................................................ 25
21.3
GENERAL CONTROL AND STATUS PINS ....................................................................... 25
22
DATA BUFFERING...................................................................................................... 27
22.1
BUFFERED MODE ..................................................................................................... 27
22.2
BUFFERED MODE HARDWARE SUPPORT ..................................................................... 27
23
PACKET HANDLING HARDWARE SUPPORT.......................................................... 29
23.1
DATA PACKET FORMAT ............................................................................................. 29
23.2
ERROR DETECTION .................................................................................................. 29
23.3
HARDWARE INTERFACE ............................................................................................ 31
24
DATA / LINE ENCODING ............................................................................................ 31
24.1
DATA ENCODING IN BUFFERED MODE......................................................................... 31
24.2
DATA ENCODING IN UN-BUFFERED MODE ................................................................... 32
25
RADIO CONTROL STATE MACHINE ........................................................................ 34
26
POWER MANAGEMENT FLOW CHART ................................................................... 36
27
FSK MODULATION FORMATS .................................................................................. 38
28
BUILT-IN TEST PATTERN GENERATOR.................................................................. 38
29
RECEIVER CHANNEL BANDWIDTH ......................................................................... 39
30
DATA RATE PROGRAMMING.................................................................................... 40
31
DEMODULATOR, BIT SYNCHRONIZER AND DATA DECISION ............................. 41
32
AUTOMATIC FREQUENCY CONTROL ..................................................................... 42
33
LINEAR IF AND AGC SETTINGS ............................................................................... 43
34
RSSI.............................................................................................................................. 44
35
CARRIER SENSE ........................................................................................................ 45
36
INTERFACING AN EXTERNAL LNA OR PA ............................................................. 45
37
GENERAL PURPOSE / TEST OUTPUT CONTROL PINS ......................................... 45
38
FREQUENCY PROGRAMMING.................................................................................. 47
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CC2400
38.1
TRANSMIT MODE ...................................................................................................... 47
38.2
RECEIVE MODE ........................................................................................................ 47
39
ALTERNATE TX IF SETTING ..................................................................................... 47
40
VCO .............................................................................................................................. 48
41
VCO SELF-CALIBRATION.......................................................................................... 48
42
OUTPUT POWER PROGRAMMING ........................................................................... 48
43
CRYSTAL OSCILLATOR ............................................................................................ 49
44
INPUT / OUTPUT MATCHING..................................................................................... 50
45
TYPICAL PERFORMANCE GRAPHS......................................................................... 50
46
SYSTEM CONSIDERATIONS AND GUIDELINES ..................................................... 53
46.1
SRD REGULATIONS.................................................................................................. 53
46.2
FREQUENCY HOPPING AND MULTI-CHANNEL SYSTEMS ................................................ 53
46.3
DATA BURST TRANSMISSIONS ................................................................................... 53
46.4
CONTINUOUS TRANSMISSIONS .................................................................................. 53
46.5
CRYSTAL DRIFT COMPENSATION ............................................................................... 53
46.6
SPECTRUM EFFICIENT MODULATION .......................................................................... 54
46.7
LOW LATENCY SYSTEMS ........................................................................................... 54
46.8
LOW COST SYSTEMS ................................................................................................ 54
46.9
BATTERY OPERATED SYSTEMS .................................................................................. 54
46.10 INCREASING OUTPUT POWER .................................................................................... 54
47
PCB LAYOUT RECOMMENDATIONS ....................................................................... 56
48
ANTENNA CONSIDERATIONS .................................................................................. 57
49
CONFIGURATION REGISTERS ................................................................................. 58
50
PACKAGE DESCRIPTION (QFN48) ........................................................................... 76
51
RECOMMENDED LAYOUT FOR PACKAGE (/QFN48)............................................. 77
52
PACKAGE THERMAL PROPERTIES......................................................................... 77
53
SOLDERING INFORMATION...................................................................................... 77
54
IC MARKING ................................................................................................................ 78
55
PLASTIC TUBE SPECIFICATION............................................................................... 80
56
CARRIER TAPE AND REEL SPECIFICATION .......................................................... 80
57
ORDERING INFORMATION........................................................................................ 80
58
GENERAL INFORMATION.......................................................................................... 81
58.1
DOCUMENT HISTORY ............................................................................................... 81
58.2
PRODUCT STATUS DEFINITIONS ................................................................................ 82
58.3
DISCLAIMER............................................................................................................. 82
58.4
TRADEMARKS .......................................................................................................... 82
58.5
LIFE SUPPORT POLICY ............................................................................................. 82
59
ADDRESS INFORMATION.......................................................................................... 83
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CC2400
1
Abbreviations
ACP
ACR
ADC
AFC
AGC
BER
BOM
bps
BT
CRC
CSMA
CSMA / CA
DAC
ESR
FH
FHSS
FIFO
FS
FSK
GFSK
IF
ISM
kbps
LNA
Mbps
MCU
NRZ
PA
PD
PCB
PN9
PLL
PRN
PRNG
RF
RSSI
RX
SPI
SRD
TBD
TDMA
TX
VCO
VGA
Adjacent Channel Power
Adjacent Channel Rejection
Analog-to-Digital Converter
Automatic Frequency Correction
Automatic Gain Control
Bit Error Rate
Bill Of Materials
bits per second
Bandwidth-Time product (for GFSK)
Cyclic Redundancy Check
Carrier Sense Multiple Access
Carrier Sense Multiple Access / Collision Avoidance
Digital-to-Analog Converter
Equivalent Series Resistance
Frequency Hopping
Frequency Hopping Spread Spectrum
First In First Out (queue)
Frequency Synthesizer
Frequency Shift Keying
Gaussian Frequency Shift Keying
Intermediate Frequency
Industrial Scientific Medical
kilo bits per second
Low Noise Amplifier
Mega bits per second
Micro Controller Unit
Non Return to Zero
Power Amplifier
Phase Detector
Printed Circuit Board
Pseudo-random Bit Sequence (9-bit)
Phase Locked Loop
Pseudo Random Number
Pseudo Random Number Generator
Radio Frequency
Received Signal Strength Indicator
Receive (mode)
Serial Peripheral Interface
Short Range Device
To Be Decided/Defined
Time Division Multiple Access
Transmit (mode)
Voltage Controlled Oscillator
Variable Gain Amplifier
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CC2400
2
Features
• 2400 – 2483 MHz RF transceiver
• GFSK and FSK modulation
• Very low current consumption (RX:
24 mA)
• Over-the-air data rates of 10 kbps,
250 kbps and 1 Mbps
• High sensitivity (-87 dBm @ 1Mbps,
-3
BER=10 )
• Agile frequency synthesizer (40 us
settling time)
• On-chip VCO, LNA and PA
• Low core supply voltage (1.6-2.0 V)
• Flexible
I/O
supply
voltage
(1.6–3.6 V) to match the signal
levels
of
the
interfacing
microcontroller
• Programmable output power
• I/Q low-IF receiver
• I/Q direct up-conversion transmitter
• Few external components
• Only reference crystal and a few
passives needed
• No external filters needed
• Programmable baseband modem
• 4-wire SPI interface
• Serial clock up to 20 MHz
• Digital RSSI output
• Packet handling hardware support
• Preamble
generator
with
programmable length
• Programmable
synchronization
word insertion/detection
• CRC computation over the data
field
• 8B/10B line coding option
• Data buffering
• 32 byte FIFO
• Provides for flexible communication
with the host controller.
• Burst transmission reduces the
average power consumption.
• Powerful and flexible development
tools available
• Fully equipped development kit
• Demonstration board reference
design with microcontroller code
• Easy-to-use
SmartRF
Studio
software for generating the CC2400
configuration data
• Small size (QFN 48 package) 7 x 7 mm
• Reference design complies with EN
300 328, EN 300 440, FCC CFR47 part
15 and ARIB STD-T66
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CC2400
3
Absolute Maximum Ratings
Min.
Max.
Units
Supply voltage, chip core,
AVDD/DVDD1.8=VDD
Supply voltage (DVDD3.3=VDDIO), digital I/O
Voltage on any pin, core
Parameter
−0.3
2.0
V
−0.3
−0.3
V
V
Voltage on any pin, digital I/O (pin no. 27-35)
−0.3
Input RF level
Storage temperature range
Reflow solder temperature
−50
3.6
VDD+0.3,
max 2.0
VDDIO+0.3,
max 3.6
10
150
260
Condition
V
dBm
°C
°C
T = 10 s
NOTE:
The supply voltage to the chip core (AVDD/DVDD1.8) should not be switched off when the digital IO (DVDD3.3)
supply voltage is still applied to the chip. If this is done, a large current will flow inside the CC2400 and the chip may
be damaged as a result.
If the core supply needs to be switched off to lower the power consumption, please see page 17 for a suggested
solution.
The absolute maximum ratings given
above should under no circumstances 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.
4
Operating Conditions
Parameter
Supply voltage, chip core,
AVDD/DVDD1.8
Supply voltage (DVDD3.3), digital
I/O, VDDIO
Recommended supply voltage, chip
core, AVDD/DVDD1.8
Recommended supply voltage
(DVDD3.3), digital I/O
Operating ambient temperature
range
Min.
Max.
Unit
1.6
Typ.
2.0
V
1.6
3.6
V
85
°C
Condition
The digital I/O voltage (DVDD3.3
pin) must match the interfacing
circuit.
1.8V
1.8V/
3.3V
−40
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CC2400
5
Electrical Specifications
Parameter
Min.
Typ.
Max.
Unit
Current Consumption,
Power Down mode (OFF)
1.5
5
µA
Current Consumption,
Idle mode (IDLE)
1.2
mA
Current Consumption,
Frequency synthesizer (FS_ON)
6.3
mA
24
mA
P=−25 dBm
11
mA
P=−5 dBm
15
mA
P=0 dBm
19
mA
Current Consumption, crystal
oscillator core
38
µA
Current Consumption,
Receive mode
Condition / Note
Oscillator core off
Current Consumption,
Transmit mode:
The output power is delivered
differentially to a 50Ω singleended load through a balun, see
also p. 50.
16 MHz, 16 pF load crystal
Table 1 Electrical specifications
6
General Characteristics
Tc = 25°C, AVDD/DVDD1.8 = 1.8 V, DVDD3.3 = 3.3V (digital I/O) if nothing else stated. Measured on Chipcon’s
CC2400EM reference design.
Parameter
RF Frequency Range
Data rate
Min.
Typ.
2400
Max.
Unit
Condition / Note
2483
MHz
Programmable in 1 MHz channel
steps.
kbps
kbps
Mbps
Data rate is
programmable/selectable, see
page 40
10
250
1
Table 2 General characteristics
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CC2400
7
RF Transmit section
Tc = 25°C, AVDD/DVDD1.8 = 1.8 V, DVDD3.3 = 3.3V (digital I/O) if nothing else stated. Measured on Chipcon’s
CC2400EM reference design.
Parameter
Binary FSK frequency deviation
Min.
Typ.
Max.
Unit
Condition / Note
0
250
500
±kHz
The frequency corresponding to
the digital "0" is denoted f0, while
f1 corresponds to a digital "1".
The frequency deviation is given
by fd=±(f1−f0)/2. The RF carrier
frequency, fc, is then given by
fc=(f0+f1)/2.
Default settings.
Power delivered to a 50 Ω singleended load through a balun. The
output power is programmable in
8 steps.
Nominal output power
0
dBm
Programmable output power range
25
dB
20 dB bandwidth
FSK
GFSK
1.2
1.0
MHz
MHz
Adjacent Channel Power (ACP)
FSK
GFSK
-30
-43
dBc
dBc
Harmonics
nd
2 order harmonic
rd
3 order harmonic
-41
-54
dBm
dBm
Spurious emission
30 - 1000 MHz
1– 12.75 GHz
1.8 – 1.9 GHz
5.15 – 5.3 GHz
-65
-41
-69
-65
Optimum load impedance
110
+ j130
-36
-30
-47
-47
dBm
dBm
dBm
dBm
Ω
Maximum output power.
Modulation is 1 Mbps, NRZ data,
± 250 kHz frequency deviation.
Maximum output power.
Modulation is 1 Mbps, NRZ data,
± 250 kHz frequency deviation.
Measured at 2 MHz offset.
At max output power delivered to
50 Ω single-ended load through a
balun. Carrier modulated with
pseudo-random data. See p.50.
Maximum output power.
Modulation is 1 Mbps FSK, NRZ
data, ±250 kHz frequency
deviation.
Complying with EN 300 440,
CFR47 Part 15 and ARIB STDT66
Differential impedance as seen
from the RF-port (RF_P and
RF_N) towards the antenna. For
matching details see “Input/
output matching” page 50 as well
as the application circuit
description on page 17.
Table 3 Transmit characteristics
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CC2400
8
RF Receive section
Tc = 25°C, AVDD/DVDD1.8 = 1.8 V, DVDD3.3 = 3.3V (digital I/O) if nothing else stated. Measured on Chipcon’s
CC2400EM reference design.
Parameter
Receiver Sensitivity at BER = 10
Min.
Typ.
Max.
Unit
Condition / Note
-87
-91
-101
dBm
dBm
dBm
Measured in a 50 Ohm singleended load through a balun. FSK,
NRZ mode used.
±250 kHz frequency deviation
±250 kHz frequency deviation
±125 kHz frequency deviation
3
dBm
-10
dB
−3
1 Mbps, 1 MHz channel BW
250 kbps, 1 MHz channel BW
10 kbps, 500 kHz channel BW
Saturation (maximum input level)
Co-channel rejection
Adjacent channel rejection (ACR)
1 Mbps
250 kbps
0
12
dB
dB
Image channel rejection
1 Mbps
250 kbps
Maximum gain in LNA.
−3
NRZ coded data, BER = 10
1 Mbps wanted signal 10 dB
above the sensitivity level,
interferer modulated like signal
(pseudo-random FSK, ± 250 kHz
deviation), interferer at operating
−3
frequency, BER = 10
FSK wanted signal 10 dB above
the sensitivity level, 1 MHz
channel spacing, interferer
modulated like signal (pseudorandom FSK, ± 250 kHz
deviation) at adjacent channel,
−3
BER = 10
FSK wanted signal 10 dB above
the sensitivity level, interferer
modulated like signal (pseudorandom FSK, ± 250 kHz
deviation) at image frequency,
−3
BER = 10 . The image channel
is centered 2MHz below the
center frequency of the desired
channel.
21
39
dB
dB
+ 2MHz
± 3MHz
± 4MHz
± 5MHz
± 10MHz
± 20 MHz
± 50MHz
20
41
50
52
55
56
59
dB
dB
dB
dB
dB
dB
dB
1Mbps FSK wanted signal at
2441 MHz, 3 dB above the
sensitivity level (except + 2 MHz,
which is 10 dB above the
sensitivity limit), jammer
modulated like signal (pseudorandom, ± 250 kHz deviation) at
± 2-39 MHz in 1 MHz steps
−3
offset, BER = 10 . Adjacent
channels and image channel are
excluded.
+ 2 MHz
± 3 MHz
± 4 MHz
± 5 MHz
± 10 MHz
± 20 MHz
± 50 MHz
48
50
55
56
59
60
64
dB
dB
dB
dB
dB
dB
dB
250 kbps FSK wanted signal at
2441 MHz, 3 dB above the
sensitivity level (except + 2 MHz,
which is 10 dB above the
sensitivity limit), jammer
modulated like signal (pseudorandom, ± 250 kHz deviation) at
± 2-39 MHz in 1 MHz steps
−3
offset, BER = 10 . Adjacent
channels and image channel are
excluded.
Selectivity (C/I)
(In-band channel rejection)
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CC2400
Parameter
Min.
Blocking / Desensitization*
(*out-of-band spurious response
rejection)
0.3 – 2.0 GHz
2.0 – 2.399 GHz
2.498 – 3.0 GHz
3 – 12.75 GHz
Typ.
Max.
Unit
Condition / Note
71
50
49
76
dB
dB
dB
dB
1 Mbps FSK wanted signal 3 dB
above the sensitivity level, sinewave interfering signal, BER =
−3
10 .
Out of band
In band
-5
-17
dBm
dBm
Image frequency suppression
56
dB
Ratio between sensitivity for a
signal at the image frequency and
the sensitivity in the wanted
channel with an inverted signal.
The image frequency is centered
-2 MHz from the center of the
wanted channel. The signal
source is 1Mbps, NRZ coded
data, ±250 kHz frequency
deviation, signal level for BER =
−3
10
Spurious reception
80
dB
Ratio between the sensitivity for
an unwanted frequency and the
sensitivity in the wanted channel.
The signal source is a 1 Mbps,
NRZ coded data, ±250 kHz
frequency deviation, swept over
all frequencies 2400 – 2483.5
−3
MHz. Signal level for BER = 10
Adjacent channels and image
channel are excluded.
Spurious emission
< 1 GHz
1 – 12.75 GHz
−70
−56
Input IIP3
-57
-47
dBm
dBm
Measured directly by applying
two tones and measuring the
resulting difference tone
amplitude.
Complying with EN 300 440,
CFR47 Part 15 and ARIB STDT66
Table 4 RF Receive characteristics
9
AFC section
Parameter
AFC range
AFC accuracy
Min.
Typ.
Max.
Unit
± 500
kHz
5
kHz
Condition / Note
For 1Mbps and 1 MHz channel
width, AFC_SETTLING=4.
Measured using an unmodulated
carrier.
Table 5 AFC characteristics
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CC2400
10 RSSI / Carrier Sense section
Parameter
Min.
Typ.
Max.
Unit
RSSI range / Carrier sense range
80
dB
RSSI settling time
RSSI accuracy
20
±4
s
dB
Condition / Note
For 1Mbps and 1 MHz channel
width.
(The range is from –100 dBm to
–20 dBm typically)
See page 44 for details
Table 6 RSSI / Carrier sense characteristics
11 IF section
Parameter
Min.
Intermediate frequency (IF)
Digital channel filter bandwidth
Typ.
Max.
Unit
1
125
Condition / Note
MHz
1000
kHz
The digital channel filter 6dBbandwidth is programmable in
steps: 125, 250, 500 and 1000
kHz. See page 39 for details.
Table 7 IF characteristics
12 Frequency Synthesizer section
Parameter
Min.
Crystal oscillator frequency
Typ.
Max.
16
Crystal frequency accuracy
requirement
20
Crystal operation
Crystal load capacitance
Condition / Note
MHz
See page 49 for details.
±ppm
The total crystal frequency
accuracy, i.e. initial tolerance plus
aging and temperature
dependency, will determine the
frequency accuracy of the
transmitted signal. 1 Mbps FSK,
250 kHz deviation.
Parallel
12
16
Crystal ESR
Crystal oscillator start-up time
Unit
C4 and C5 are loading
capacitors, see page 49
20
pF
60
Ω
1.13
ms
-108
-114
-114
dBc/Hz
dBc/Hz
dBc/Hz
50
kHz
Phase noise
PLL loop bandwidth
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16 pF recommended
16 pF load
Note: This time can be reduced to
15 s by enabling the XOSC core
in power-down using the
MANAND register.
Unmodulated carrier
At ±1 MHz offset from carrier
At ±2 MHz offset from carrier
At ±5 MHz offset from carrier
Page 11 of 83
CC2400
Parameter
Min.
Typ.
Max.
Unit
Condition / Note
PLL lock time (RX / TX turn-on
time)
40
µs
Until within ± 10 kHz
Step size is 1MHz, no calibration.
Note: Calibration should be
performed for frequency changes
> 8 MHz.
PLL turn-on time from IDLE mode,
crystal oscillator on
100
µs
Crystal oscillator running.
Calibration time included.
Table 8 Frequency synthesizer characteristics
13 Digital Inputs/Outputs
Parameter
Min.
Typ.
Max.
Unit
Condition / Note
Signal levels are referred to the
voltage level at the pin DVDD3.3.
Logic "0" input voltage
0
0.3*
DVDD
V
Logic "1" input voltage
0.7*
DVDD
DVDD
V
Logic "0" output voltage
0
0.4
V
Logic "1" output voltage
2.5
DVDD
V
Logic "0" input current
NA
−1
µA
Output current −8 mA,
3.3 V supply voltage
Output current 8 mA,
3.3 V supply voltage
Input signal equals GND
Logic "1" input current
NA
1
µA
Input signal equals DVDD
DIO setup time
20
ns
DIO hold time
10
ns
TX un-buffered mode, minimum
time DIO must be ready before
the positive edge of DCLK
TX un-buffered mode, minimum
time DIO must be held after the
positive edge of DCLK
Serial interface (SCLK, SI, SO and
CSn) timing specification
See Table 12 page 22
Table 9 Digital input/output characteristics
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CC2400
NC
NC
39
38
37 NC
NC
XOSC16_Q2
42
40
XOSC16_Q1
43
41 AVDD_XOSC
AVDD_IF1
44
ATEST2
46
45 R_BIAS
ATEST1
47
48 AVDD_CHP
14 Pin Assignment
VCO_GUARD 1
36 NC
AVDD_VCO 2
35 GIO6
AVDD_PRE 3
34 SO
AVDD_RF1 4
33 SI
32 SCLK
GND 5
QLP48
CC2400
7x7
RF_P 6
TXRX_SWITCH 7
31 CSn
30 DCLK/FIFO
RF_N 8
29 DIO/PKT
GND 9
28 TX
AVDD_SW 10
27 RX
NC 11
26 DVDD1.8
NC 12
25 DVDD3.3
24 DSUB_CORE
23 DSUB_PADS
22 DGND
21 GIO1
20 BT/GR
19 DGUARD
18 DGND_GUARD
17 DVDD_ADC
16 AVDD_ADC
15 AVDD_IF2
NC
14 AVDD_RF2
13
AGND
Exposed die
attach pad
Figure 1 CC2400 Top View
Pin no.
-
Pin name
AGND
Pin type
Ground (analog)
Description
Exposed die attach pad. Must be connected to solid ground
plane
Connection of guard ring for VCO shielding
1
VCO_GUARD
Power (Analog)
2
AVDD_VCO
Power (Analog)
Power supply for VCO
3
AVDD_PRE
Power (Analog)
Power supply for Prescaler
4
AVDD_RF1
Power (Analog)
Power supply for RF front-end
5
GND
Ground (Analog)
Grounded pin for RF shielding
6
RF_P
RF I/O
7
TXRX_SWITCH
8
RF_N
RF I/O
9
GND
Ground (Analog)
Grounded pin for RF shielding
10
AVDD_SW
Power (Analog)
Power supply connection
Power (Analog)
Positive RF input/output signal to LNA/from PA in
receive/transmit mode
Common supply connection for RF front-end. Must be
connected to RF_P and RF_N externally through a DC path.
Negative RF input/output signal to LNA/from PA in
receive/transmit mode
SWRS042A
Page 13 of 83
CC2400
Pin no.
11
NC
Pin name
Pin type
---
No Connect
12
NC
---
No Connect
13
NC
---
14
AVDD_RF2
15
AVDD_IF2
Power (Analog)
Power supply for transmit IF chain
16
AVDD_ADC
Power (Analog)
Power supply connection of ADCs and DACs
Power supply for digital part of receive ADCs
Power (Analog)
Description
No Connect
Power supply for receive and transmit mixers
17
DVDD_ADC
Power (Digital)
18
DGND_GUARD
Ground (Digital)
Ground connection for digital noise isolation
19
DGUARD
Power (Digital)
Power supply connection for digital noise isolation
20
BT/GR
21
GIO1
22
DGND
Ground (Digital)
Ground connection for digital modules
23
DSUB_PADS
Ground (Digital)
Substrate connection for digital I/O’s
24
DSUB_CORE
Ground (Digital)
Substrate connection for digital modules
25
DVDD3.3
Power (Digital)
Power supply for digital I/O’s
26
DVDD1.8
Power (Digital)
Power supply for digital modules
27
RX
Digital Input
28
TX
Digital I/O
Strobe signal for TX mode. Connect to ground when not used.
29
DIO/PKT
Digital I/O
Data input/output in un-buffered mode or packet handling
control signal. Configure as output when not used.
30
DCLK/FIFO
Digital Input
Digital I/O
Digital Output
Selection of Built-in-Test or Generic Radio (normal operation).
Connect to ground for normal operation (NOTE: For Chipcon
internal use only.)
General digital I/O pin. Configure as output when not used.
See Table 18
Strobe signal for RX mode. Connect to ground when not used.
Data clock output signal in un-buffered mode or FIFO control
signal. Leave open when not used.
31
CSn
Digital Input
SPI: Chip Select
32
SCLK
Digital Input
SPI: Serial data clock
33
SI
Digital Input
34
SO
Digital Output
35
GIO6
Digital Output
36
NC
---
No Connect
37
NC
---
No Connect
38
NC
---
No Connect
39
NC
---
No Connect
40
NC
---
41
AVDD_XOSC
Power (Analog)
42
XOSC16_Q2
Analog output
43
XOSC16_Q1
Analog input
44
AVDD_IF1
45
R_BIAS
Analog Output
46
ATEST2
Analog I/O
Analog test I/O for prototype and production testing. Leave not
connected when not used.
47
ATEST1
Analog I/O
Analog test I/O for prototype and production testing. Leave not
connected when not used.
48
AVDD_CHP
Power (Analog)
Power (Analog)
SPI: Slave Input
SPI: Slave Output
General digital output pin. See Table 18
No Connect
Power supply for 16 MHz crystal oscillator
16 MHz crystal oscillator
16 MHz crystal oscillator or external clock input
Power supply connection of receive IF chain
Connection for external precision bias resistor
Power supply for phase detector and charge pump
NOTES:
The exposed die attach pad must be connected to a solid ground plane as this is the main ground connection for the
chip.
The digital inputs SCLK, SI and CSn are high-impedance inputs (no internal pull-up) and should have external pullups if not driven. RX and TX should have external pull-down if not driven (to prevent the state machine from being
trigged). SO is high-impedance when CSn is high. External pull-up should be used at SO to prevent floating input at
the microcontroller.
SWRS042A
Page 14 of 83
CC2400
15 Circuit Description
LNA
ADC
DIGITAL
DEMODULATOR
- Digital RSSI
- Gain Control
- Image Suppression
- Channel Filtering
- Demodulation
SmartRF 
CC2400
FREQ
SYNTH
0
90
TX POWER CONTROL
DAC
Power
Control
PA
Σ
CONTROL LOGIC
AGC CONTROL
TX/RX CONTROL
DIGITAL
INTERFACE /
FIFO
TO MICROCONTROLLER
ADC
DIGITAL
MODULATOR
- Data Filtering
- Modulation
- Power Control
DAC
XOSC
On-chip
BIAS
16 MHz
Figure 2. CC2400 simplified block diagram
A simplified block diagram of CC2400 is
shown in Figure 2.
programmable carrier sense indicator with
output on either GIO1 or GIO6.
CC2400 features a low-IF receiver. The
In transmit mode the baseband signal is
directly up-converted quadrature (I and Q)
and then fed to the power amplifier (PA).
received RF signal is amplified by the lownoise amplifier (LNA) and down-converted
in quadrature (I and Q) to the intermediate
frequency (IF). At IF (1 MHz), the I/Q
signal is filtered and amplified, and then
digitized by the ADCs. Automatic gain
control,
final
channel
filtering,
demodulation and bit synchronization is
performed digitally.
CC2400 outputs (in un-buffered mode only)
the digital demodulated data on the DIO
pin. A synchronized data clock is then
available at the DCLK pin. In buffered
mode the demodulated data is sent to a
FIFO and is accessible through the SPI
interface. RSSI is available in digital
format and can be read via the serial
interface. The RSSI also features a
The TX IF signal is frequency shift keyed
(FSK). Optionally Gaussian filtering can be
used enabling GFSK. The BT of the
Gaussian filter is 0.5 for a datarate of
1 Mbps.
The internal T/R switch circuitry simplifies
the antenna interface and matching. The
antenna connection is differential. The
biasing of the PA and LNA is done by
connecting TXRX_SWITCH to RF_P and
RF_N through an external DC path.
The frequency synthesizer includes a
completely on-chip LC VCO and a 90
degrees phase splitter for generating the
SWRS042A
Page 15 of 83
CC2400
LO_I and LO_Q signals to the downconversion mixers in receive mode and
up-conversion mixers in transmit mode.
The VCO operates in the frequency range
4800 – 4966 MHz, and the frequency is
divided by two when split in I and Q.
A crystal must be connected to
XOSC16_Q1 and XOSC16_Q2 and
generates the reference frequency for the
synthesizer. A PLL lock signal is available
via the GIO pins.
The digital baseband includes support for
packet handling and data buffering.
The 4-wire SPI serial interface is used for
configuration (and data interface in
buffered mode). A few digital I/O lines can
be configured for use with packet handling
strobe and interrupt signals.
SWRS042A
Page 16 of 83
CC2400
16 Application Circuit
Few external components are required for
the operation of CC2400. A typical
application circuit is shown in Figure 3. A
description of the external components
referring to Figure 3 are described in
Table 10. The bill of materials (BOM) is
given in Table 11.
16.3 Crystal
An external crystal with input and output
loading capacitors (C421 and C431) is
used for the crystal oscillator. See page 49
for details.
Good PCB layout is vital for proper
operation, please see the section on PCB
Layout Recommendations on page 56 for
more details.
16.4 Digital I/O
The supply voltage for the digital I/O must
match the interfacing microcontroller. The
digital I/Os of CC2400 can interface
microcontrollers with supply voltages in
the range 1.6 – 3.6 V.
16.1 Input / output matching
The RF input/output is high impedance
and differential. The optimum differential
load for the RF port is listed on page 8.
When using an unbalanced antenna like a
monopole, a balun should be used in
order to get optimum performance. The
balun can be implemented using low-cost
discrete inductors and capacitors. The
balun consists of C61, C62, C71, C81,
L61, L62 and L72, and will match the RF
input/output to 50 Ω, see Figure 3. L61
and L62 also provide DC biasing of the
LNA/PA input/output. L71 is used to
isolate the TXRX_SWITCH pin. An
internal T/R switch circuit is used to switch
between the LNA and the PA. See
“Input/output matching” on page 50 for
more details.
If a balanced antenna, like a folded dipole,
is used, the balun can be omitted. If the
antenna also provides a DC path from the
TXRX_SWITCH pin to the RF pins,
inductors are not needed for DC biasing.
The L71 isolation inductor should still be
used to avoid antenna reflections. Figure 4
shows a typical application circuit with
differential antenna. The dipole has a
virtual ground point, hence bias is
provided without degradation in antenna
performance. Please note that a
differential antenna is generally larger than
an equivalent single-ended antenna.
16.5 Power supply decoupling and
filtering
Proper power supply decoupling must be
used for optimum performance. The
placement and size of the decoupling
capacitors and the power supply filtering
are very important to achieve the best
performance in an application. Chipcon
provides a compact reference design that
should be followed very closely.
16.6 Power supply switching
As described in a note in the Absolute
Maximum Ratings section, the voltage
supply to the chip core should not be
switched off separately from the I/O supply
voltage.
If it is necessary to switch the core power
supply off, for instance to save the power
dissipated in the 1.8V regulator, the I/O
supply should be turned off as well. This
can be done quite easily by running the
I/O supply from a microcontroller I/O pin.
Current drawn on the I/O supply is just a
few milliamps, so an ordinary I/O pin
should have no problems in sourcing this
current. Power sequencing should be
performed so that both supplies are turned
on and off simultaneously.
16.2 Bias resistor
The bias resistor R451 is used to set an
accurate bias current for the chip.
SWRS042A
Page 17 of 83
CC2400
Ref
C71
C61
C81
C62
C421
C431
L61
L62
L71
L81
R451
XTAL
Description
Front-end bias decoupling and match, see page 50
Discrete balun and match, see page 50
Discrete balun and match, see page 50
DC block to antenna and match
16MHz crystal load capacitor, see page 49
16MHz crystal load capacitor, see page 49
DC bias and match, see page 50
DC bias and match, see page 50
RF blocking inductor, see page 50
Discrete balun and match, see page 50
Precision resistor for current reference generator
16MHz crystal, see page 49
Table 10. Overview and description of external components for an unbalanced antenna
(balun implemented with low cost discrete components)
AVDD=1.8V AVDD=1.8V
C431
C421
R451
XTAL
37
38
39
40
41
NC
NC
NC
NC
AVDD_XOSC
AVDD_RF1
SI
GND
CC2400
RF_P
TXRX_SWITCH
SCLK
CSn
DCLK/FIFO
RF_N
DIO/PKT
GND
TX
AVDD_SW
RX
DSUB_PADS
DSUB_CORE
DGND
GIO1
BT/GR
DGUARD
DVDD_ADC
NC
AVDD_IF2
NC
NC
DVDD1.8
DVDD3.3
36
35
34
33
SPI-bus
32
31
30
29
28
Optional
digital
interface
27
26
DVDD=1.8V
25
DVDD Digital I/O
=1.8 / 3.3V
24
23
21
22
20
19
17
18
16
15
13
14
AVDD=1.8V
SO
AVDD_ADC
12
NC
GIO6
AVDD_PRE
AVDD_RF2
11
AVDD_VCO
DGND_GUARD
C81
10
XOSC16_Q2
9
L81
42
8
43
C62
L71
XOSC16_Q1
7
L61
AVDD_IF1
C71
6
L62
45
5
VCO_GUARD
44
C61
ATEST2
4
R_BIAS
3
46
2
ATEST1
AVDD
_CHP
1
Antenna
(50 Ohm)
47
48
AVDD=1.8V
DVDD=1.8V
Figure 3 Typical application circuit with discrete balun for interfacing single-ended
antenna
SWRS042A
Page 18 of 83
CC2400
AVDD=1.8V AVDD=1.8V
C431
C421
R451
XTAL
37
38
39
40
41
NC
NC
NC
NC
AVDD_XOSC
NC
GIO6
AVDD_PRE
SO
AVDD_RF1
SI
GND
CC2400
RF_P
TXRX_SWITCH
SCLK
CSn
DCLK/FIFO
RF_N
DIO/PKT
GND
TX
RX
DSUB_PADS
DSUB_CORE
DGND
GIO1
DVDD1.8
DVDD3.3
36
35
34
SPI-bus
33
32
31
30
Optional
digital
interface
29
28
27
26
DVDD=1.8V
25
DVDD Digital I/O
=1.8 / 3.3V
24
23
21
22
20
19
17
18
16
15
13
14
AVDD=1.8V
BT/GR
DGUARD
NC
DVDD_ADC
NC
AVDD_ADC
NC
DGND_GUARD
AVDD_SW
AVDD_IF2
12
AVDD_VCO
AVDD_RF2
11
XOSC16_Q2
9
10
42
8
XOSC16_Q1
7
43
L71
44
L61
VCO_GUARD
AVDD_IF1
6
45
5
R_BIAS
4
ATEST2
3
46
2
ATEST1
AVDD
_CHP
1
Folded
dipole
antenna
47
48
AVDD=1.8V
DVDD=1.8V
Figure 4 Typical application circuit with differential antenna (folded dipole)
Item
Single ended output, discrete
balun
Differential antenna
C62
C61
C81
C71
C421
C431
L61
L62
L71
L81
R451
XTAL
5.6 pF, +/- 0.25pF, NP0, 0402
0.5 pF, +/- 0.25pF, NP0, 0402
0.5 pF, +/- 0.25pF, NP0, 0402
100 nF, 10%, X5R, 0402
18 pF, 5%, NP0, 0402
18 pF, 5%, NP0, 0402
7.5 nH, 5%, Monolithic/multilayer, 0402
5.6 nH, 5%, Monolithic/multilayer, 0402
27 nH, 5%, Monolithic/multilayer, 0402
7.5 nH, 5%, Monolithic/multilayer, 0402
43 kΩ, 1%, 0402
16 MHz crystal, 16 pF load (CL)
Not used
Not used
Not used
100 nF, 10%, X5R, 0402
18 pF, 5%, NP0, 0402
18 pF, 5%, NP0, 0402
27 nH, 5%, Monolithic/multilayer, 0402
Not used
27 nH, 5%, Monolithic/multilayer, 0402
Not used
43 kΩ, 1%, 0402
16 MHz crystal, 16 pF load (CL)
NOTE: Decoupling components are not included.
Table 11. Bill of materials for the application circuits
SWRS042A
Page 19 of 83
CC2400
17 Configuration Overview
CC2400 can be configured to achieve
optimum
performance
for
different
applications. Through the programmable
configuration registers the following key
parameters can be programmed:
•
•
•
•
•
Receive / transmit mode
RF frequency
RF output power
FSK frequency deviation
Power-down / power-up mode
• Crystal oscillator power-up / power
down
• Data rate and line coding (NRZ,
8B/10B coding)
• Synthesizer lock indicator mode
• Digital RSSI
• FSK / GFSK modulation
• Data buffering
• Packet handling hardware support
18 Configuration Software
Chipcon provides users of CC2400 with a
software program, SmartRF® Studio
(Windows interface) that generates all
necessary CC2400 configuration data,
based on the user's selections of various
parameters. These hexadecimal numbers
will then be the necessary input to the
microcontroller for the configuration of
CC2400.
Figure 5 shows the user interface of the
CC2400 configuration software.
Figure 5. SmartRF® Studio user interface
SWRS042A
Page 20 of 83
CC2400
19 4-wire Serial Configuration Interface
CC2400 is configured via a simple 4-wire
SPI-compatible interface (SI, SO, SCLK
and CSn) where CC2400 is the slave. This
interface is also used as data interface in
buffered mode (see page 27).
There are 44 16-bit configuration registers,
9 Command Strobe Registers, and one
register to access the FIFO. Each register
has a 7-bit address. The FIFO (32 bytes)
is 8 bits wide. A Read/Write bit indicates a
read or a write operation and forms the 8bit address field together with the 7-bit
address.
Some registers are termed Command
Strobe Registers. By addressing a
Command
Strobe
register
internal
sequences will be started. These
commands can be used to quickly change
from RX mode to TX mode, for example.
A full configuration of CC2400 requires
sending 44 data frames of 24 bits each (7
address bits, R/W bit and 16 data bits).
The time needed for a full configuration
depend on the SCLK frequency. With a
SCLK frequency of 20 MHz the full
configuration is done in less than 5 µs.
Setting the device in power down mode
requires addressing one command strobe
register only, and will in this case take less
than 0.4 µs. All registers except the strobe
registers are also readable.
In each write-cycle, 24 bits are sent on the
SI-line. The bit to be sent first is the R/W
bit (0 for write, 1 for read). The next seven
bits are the address-bits (A6:0). A6 is the
MSB (Most Significant Bit) of the address
and is sent first. The 16 data-bits are then
transferred (D15:0). During address and
data transfer the CSn (Chip Select, active
low) must be kept low. See Figure 6.
The timing for the programming is shown
in Figure 6 with reference to Table 12. The
clocking of the data on SI into the CC2400
is performed on the positive edge of
SCLK.
The data word is loaded into the internal
configuration register, when the last bit,
D0, of the 16 data bits has been written.
The configuration data will be retained
during a programmed power-down mode,
but not when the power-supply is turned
off. The registers can be programmed in
any order.
The configuration registers can also be
read by the microcontroller via the same
configuration interface. The R/W bit must
be set high to initiate the data read-back,
then the seven address bits are sent.
CC2400 then returns the data from the
addressed register. SO is used as the
data output and must be configured as an
input by the microcontroller.
The command strobe register is accessed
in the same way as for a write operation,
but no data is transferred. That is, only the
R/W bit and the seven address bits are
written before CSn should be set high.
Figure 7 shows a summary of read and
write operations. A register read/write can
be terminated after one byte if only the
most significant byte is required. A register
can also be accessed repeatedly without
writing the address again. The buffer FIFO
(8 bit wide, 32 bytes) can be written
continuously by simply writing new bytes
over and over. The internal data pointer is
then updated for every written byte. The
session is terminated when the CSn is set
high.
Please note that a longer hold time, tps, is
needed before setting CSn high when
accessing the FIFO in buffered mode.
During the transfer of the address, the
CC2400 returns a status byte on the SO
line containing some important flags. This
is shown in Table 13.
SWRS042A
Page 21 of 83
CC2400
tps
tsp
tch
tcl
tsd
thd
tns
SCLK:
CSn:
Write to register:
SI
SO
0
A6
A5
A4
A3
A2
A1
A0
S7
S6
S5
S4
S3
S2
S1
S0
X
DW15 DW14 DW13 DW12 DW11 DW 10
DW 9
DW 8
X
DW 7
DW 6
DW 5
DW 4
DW 3
DW 2
DW 1
DW 0
X
DR6
DR5
DR4
DR3
DR2
DR1
DR0
DR15
X
Read from register:
SI
1
A6
A5
A4
A3
A2
A1
A0
SO
S7
S6
S5
S4
S3
S2
S1
S0
X
DR15
DR14 DR13 DR12 DR11 DR10
DR9
DR8
DR7
Figure 6. SPI timing diagram
CSn:
Command strobe:
ADDR
Read or write a whole register (16 bit):
ADDR
DATA8MSB
Read or write 8 MSB of a register:
ADDR
DATA8MSB
ADDR
DATA8MSB
DATA8LSB
DATA8MSB
DATA8LSB
...
ADDRFIFO
DATAbyte0
DATAbyte1
DATAbyte2
DATAbyte3
...
Read or write a whole register continuously:
Read or write n bytes from/to RF FIFO:
DATA8LSB
DATA8MSB
DATA8LSB
DATAbyte n-2 DATAbyte n-1
Figure 7. Configuration registers write and read operations via SPI
Parameter
SCLK, clock
frequency
SCLK low
pulse
duration
SCLK high
pulse
duration
CSn setup
time
CSn hold
time 1
CSn hold
time 2
Symbol
Min
fSCLK
Max
Units
20
MHz
Conditions
tcl,min
25
ns
The minimum time SCLK must be low.
tch,min
25
ns
The minimum time SCLK must be high.
tsp
25
ns
tns
25
ns
tps
300
ns
SI setup time
tsd
25
ns
SI hold time
thd
25
ns
Rise time
trise
100
ns
The minimum time CSn must be low before
positive edge of SCLK.
The minimum time CSn must be held low after the
last negative edge of SCLK.
In buffered mode: The minimum time CSn must be
held low after the last positive edge of SCLK. This
only applies to FIFO accesses.
The minimum time data on SI must be ready
before the positive edge of SCLK.
The minimum time data must be held at SI, after
the positive edge of SCLK.
The maximum rise time for SCLK and CSN
Fall time
tfall
100
ns
The maximum fall time for SCLK and CSn
Note: The set-up- and hold-times refer to 50% of VDD.
Table 12. SPI timing specification
SWRS042A
Page 22 of 83
CC2400
Bit #
Name
Description
7
-
Reserved, ignore value
6
XOSC16M_STABLE
Indicates whether the 16 MHz oscillator is running ('1') or not
5
RESERVED
Reserved
4
SYNC_RECEIVED
Indicates whether a sync word has been received or not so far in
the RX operation
3
CRC_OK
Indicates whether the next two bytes in the FIFO will make the
CRC calculation successful or not:
0: CRC not OK or CRC off
1: CRC OK
2
FS_LOCK
Indicates whether the frequency synthesiser is in lock ('1') or not.
1:0
RESERVED[1:0]
Reserved
Table 13. Status byte returned during address transfer
SWRS042A
Page 23 of 83
CC2400
20 Overview of Configurations and Hardware Support
The CC2400 can be configured for different
data interfaces, coding schemes and
packet handling hardware support.
Table 14 below gives a summary of the
possibilities.
Data
interface
Data coding
Packet handling support
Buffered
NRZ
TX:
• Preamble generation
• Sync word insertion
• CRC computation and insertion
(32 byte FIFO
accessed
through the
SPI interface)
8/10 code
RX:
• Sync Word detection
• CRC computation and check
Manchester
Un-buffered
NRZ
(DIO and
DCLK
synchronous
interface)
RX:
• Sync Word detection
Manchester
Table 14. Configurations and hardware support
SWRS042A
Page 24 of 83
CC2400
21 Microcontroller Interface and Pin Configuration
Used in a typical system, CC2400 will
interface to a microcontroller. This
microcontroller must be able to:
• Program CC2400 into different modes
and read back status information via
the 4-wire SPI-bus configuration
interface (SI, SO, SCLK and CSn). In
buffered mode the data signal is also
transmitted through the SPI-bus
• Interface
to
the
bi-directional
synchronous data signal interface (DIO
and DCLK) if un-buffered data
transmission is to be used
• Optionally interface to the general
control and status pins (RX, TX, FIFO,
PKT, GIO1 and GIO6) if the hardware
supported packet handling functions
are to be used
• Optionally the microcontroller can
monitor the general I/O pins (GIO1,
GIO6) for frequency lock status, carrier
sense
status,
or
other
status
information
• Optionally, the microcontroller can read
back digital RSSI value and other
status information via the 4-wire SPI
interface
21.1 Configuration interface
The microcontroller interface is shown in
Figure 8. The microcontroller uses a
minimum of 4 I/O pins for the SPI
configuration interface (SI, SO, SCLK and
CSn). All other pins are optional. SO
should be connected to an input at the
microcontroller. SI, SCLK and CSn must
be microcontroller outputs.
The microcontroller pins connected to SI,
SO and SCLK can be shared with other
SPI-interface devices. SO is a high
impedance output as long as CSn is not
activated (active low).
CSn should have an external pull-up
resistor or be set to a high level during
power down mode in order to prevent the
input from floating. SI and SCLK should be
set to a defined level to prevent the input
from floating.
21.2 Signal interface in un-buffered
mode
A bi-directional pin (DIO) is used for data
to be transmitted and received. DCLK
providing the data timing should be
connected to a microcontroller input.
The data is clocked in/out at the positive
edge of DCLK.
21.3 General control and status pins
Optionally, in buffered mode, the FIFO pin
can
be
used
to
interrupt
the
microcontroller at full/empty FIFO. This pin
should then be connected to a
microcontroller interrupt pin.
Optionally, using the packet handling
support, the PKT pin can be used in
buffered
mode
to
interrupt
the
microcontroller when a sync word is
detected (RX mode) and packet is
transmitted (TX mode). This pin should
then be connected to a microcontroller
interrupt pin.
The polarity of FIFO and PKT can be
controlled by the INT register (address
0x23).
Optionally, the RX and TX pins can be
used to change the operating mode of
CC2400 as an alternative to using the SPI
interface strobe commands. These pins
should
then
be
connected
to
microcontroller output pins. If the RX and
TX pins are not used, they should be
grounded in order to prevent accidental
change of mode.
Optionally, the GIO1 and GIO6 can be
used to monitor several status signals as
selected by the IOCFG register. The GIO6
pin
should
be
connected to a
microcontroller input pin. See Table 18 for
available signals.
Table 15 gives a summary of the possible
pin configurations in the different operation
modes.
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Page 25 of 83
CC2400
Pin name
SCLK
SI
SO
CSn
DCLK/
FIFO
30
O
FIFO
RX
TX
GIO1*
GIO6*
31
I
CSn
DIO/
PKT
29
I/O
-
Pin number
Direction
Buffered
mode
Buffered
mode with
Packet
handling
Un-buffered
mode
32
I
SCLK
33
I
SI
34
O
SO
27
I
(RX)
28
I
(TX)
21
O
(GIO1)
35
O
(GIO6)
SCLK
SI
SO
CSn
PKT
FIFO
(RX)
(TX)
(GIO1)
(GIO6)
SCLK
SI
SO
CSn
DIO
DCLK
(RX)
(TX)
(GIO1)
(GIO6)
NOTE: Pin functions in parentheses are optional
* The use of GIO1 and GIO6 are selected in register IOCFG (address 0x08)
Table 15. Pin configuration
Buffered RF Mode:
CC2400
CSn
SI
SO
SCLK
Unbuffered RF Mode:
Data &
Control
µC
CC2400
GIO1
MOSI
MISO
SCLK
CSn
SI
SO
SCLK
GIO1
MOSI
MISO
SCLK
DIO/PKT
DCLK/FIFO
Other Circuit
CSn
SI
SO
SCLK
µC
Control
Data
GIO2
Full hardware support for packet handling :
CC2400
Data &
Control
µC
CSn
SI
SO
SCLK
GIO1
MOSI
MISO
SCLK
DIO/PKT
DCLK/FIFO
RX
TX
GIO1
GIO6
GIO2
GIO3
GIO4
GIO5
GIO6
GIO7
Control
Figure 8. Microcontroller interface
SWRS042A
Page 26 of 83
CC2400
22 Data Buffering
The CC2400 can be used with a buffered or
un-buffered data interface. The data
buffering mode is controlled by the
GRMDM.PIN_MODE[1:0] bits (register
address 0x20).
In un-buffered mode a synchronous data
clock is provided by CC2400 at the DCLK
pin, and the DIO pin is used as data
input/output (see Figure 8).
22.1 Buffered mode
In the buffered mode a 32-byte First-in
First-Out (FIFO) register block is used for
data to be transmitted and data received.
The FIFO is accessed through the
FIFOREG register (address 0x70) using
the SPI interface. Multiple bytes can be
written to the FIFO without repeating the
address if the CSn line is held low.
The crystal oscillator must be running
when accessing the FIFO.
By using the FIFO buffer the data can be
transmitted in bursts. The buffered mode
will therefore offload the host controller
keeping the SPI data rate much lower than
the data rate on the air. This gives also a
great advantage in reducing the current
consumption as the transmitter and
receiver are enabled only in short periods.
It also allows the SPI to operate faster
than the data rate, providing more time for
the MCU to work between data transfers.
More than 32 bytes can be received if the
FIFO is read during reception. In the same
way more than 32 bytes can be
transmitted if new data is written into the
FIFO during transmission. Figure 9 shows
the ways the FIFO can be used during
transmission.
22.2 Buffered mode hardware support
In the buffered mode the FIFO pin can be
used as an interrupt output to assist the
microcontroller in supervising the FIFO.
mode. The threshold (FIFO_THRESHOLD)
is set in INT.FIFO_THRESHOLD[4:0].
In receive mode there will be an interrupt
when the number of received bytes in the
FIFO reaches FIFO_THRESHOLD. The
default value is 30, giving an interrupt
when 30 bytes are received. If the FIFO
becomes full (32 bytes) before it is read,
the reception will be terminated (goes to
the FS_ON state).
In transmit mode there will be an interrupt
when the number of bytes left in the FIFO
reaches 32 - FIFO_THRESHOLD. For the
default value this will happen when there
are 2 bytes left. The transmission is
terminated when the FIFO runs empty
(goes to the FS_ON state). Note that in
order for the FIFO pin to give an interrupt
in transmit mode the number of bytes
must first exceed 32 - FIFO_THRESHOLD.
The FIFO pin activity is illustrated in
Figure 10.
The INT.FIFO_POLARITY bit sets the
polarity of the interrupt signal.
In TX mode, the FIFO pin goes low when
a transmission starts and the preamble is
sent. It will stay low as long as the FIFO is
empty. When data is written to the FIFO, it
will go high. If the number of bytes in the
FIFO goes below the FIFO_THRESHOLD,
the FIFO pin will go low again. If the FIFO
pin goes low, it will stay low until the CRC
has been transmitted.
FIFO_FULL and FIFO_EMPTY signals are
available on the general-purpose I/O pins.
These two signals are affected by
FIFO_THRESHOLD.
In transmit mode, FIFO_EMPTY is low if
the number of bytes in the FIFO is more
than 32-FIFO_THRESHOLD. In receive
mode, FIFO_EMPTY goes low when there
is more than 1 byte in the FIFO.
The FIFO pin can be programmed to give
an interrupt when the FIFO is nearly
empty in TX mode, and nearly full in RX
SWRS042A
Page 27 of 83
CC2400
FIFO_FULL is high if the number of bytes
in the FIFO is greater or equal to
FIFO_THRESHOLD.
Packet #0
FIFO
Data to
packet
engine
Data
f rom
MCU
a) Single packet in FIFO
Packet #0
FIFO
Data
pending
f rom MCU
Data already sent
to packet engine
b) Packet longer than FIFO
Figure 9. Ways in which the FIFO can be used during transmit mode
d,
b e ke e
ro loc rob
t
s
t
N LL s
O P RX
S
FS
RF data
nc
Sy
Preamble
d
or
w
Sync word
t
de
te
ec
d
h
ac
re
go
s
te
by ld
FO ho
FI res
th
s
te
by ld
o
O
F h
FI res
th
un
r
de
Data
PKT
RX mode:
FIFO
N
O
FS
e
,
ed
ck e
lo trob
L s
PL T X
S
b
ro
st
h
ac
re
s
te
by l d
o
O
F h
FI res
th
m
ns
FI
FO
s
is
n
io
y
pt
tra
em
et te
ck ple
a
P om
c
MCU data
TX mode:
PKT
FIFO
Figure 10. FIFO and PKT timing diagram
SWRS042A
Page 28 of 83
CC2400
23 Packet Handling Hardware Support
The CC2400 has built-in hardware support
for packet oriented radio protocols.
The buffered mode packet handling
support can in transmit mode be used to
construct the data packet:
• Add a programmable number of
preamble bytes
• Add a synchronization word
• Compute and add a CRC
computed over the data field
In receive mode the packet handling
support can be used to de-construct the
data packet:
• Synchronization word detection
• Compute and check the received
CRC
is required, Chipcon recommends that
FSK be used at 1 Mbps instead of GFSK.
GRMDM.
PRE_BYTES[2:0]
000
001
010
011
100
101
110
111
0*
1
2
4
8
16
32
Infinitely until TX
GRMDM.PRE_BYTES
[2:0] is set to 000
* Should not be used if packet reception is to be
used. Use to terminate infinite transmission (111).
The length of the synchronization word is
programmable as shown below.
The packet handling support can be
combined with the 8/10 line-encoding
scheme. The 8/10 coding will apply to the
data field (FIFO data) of the packet only
(and CRC).
In un-buffered mode the synchronization
word detection can be used to mute DCLK
until a valid sync word is received.
23.1 Data packet format
The format of the data packet can be
configured, and can consist of the
following items:
•
•
•
•
Preamble
Synchronization word
Data
CRC
See Table 16 and Figure 11 for details.
The preamble pattern is ‘(0)101010…’.
The first bit in the preamble is always the
same as the first bit in the synchronization
word. The length of the preamble is
programmable.
The
default
and
recommended length is 4 bytes.
When using GFSK modulation at 1 Mbps,
Chipcon recommends using a preamble
length of 32 bytes in order to avoid a high
level of bit errors. If low packet overhead
Number of bytes
(8 bits)
Number of bits
GRMDM.
SYNC_WORD_SIZE
[1:0]
00
01
10
11
8
16
24
32
The
synchronization
word
is
programmable in the SYNCL and SYNCH
registers. The default (and recommended)
synchronization word length is 32 bits,
which gives high immunity against false
synchronization word indication. If lower
immunity can be accepted, one can
reduce the length to 16 bits. (However,
using 8 bits will typically give too many
false synchronization word indications.)
A threshold on the number of bits in error
when receiving the synchronization word
can
be
programmed
in
GRMDM.SYNC_ERRBITS_ALLOWED[1:0]
in the range 0 – 3. (A threshold of 0 is
default.)
23.2 Error detection
When the CRC is enabled it will be
calculated based on the data field of the
packet, i.e. not including the preamble or
the
synchronization
word.
When
transmitting the packet the CRC is
appended after the last data byte in the
SWRS042A
Page 29 of 83
CC2400
data field, i.e. when the FIFO becomes
empty.
When a packet is being received the CRC
is calculated as the data is read out of the
FIFO. When all data is read, the next two
bytes in the FIFO are the CRC.
Packet field
Use
Length
GRMDM register
configuration bits
Preamble
Mandatory
≥ 1 byte
If the reception of the packet is error free,
the PKTSTATUS.CRC_OK flag is set (also
available on the GIO1 and GIO6 pins).
The CRC polynomial is:
x16 + x15 + x2 + 1
Synchronisation word
Mandatory
1, 2, 3 or 4 bytes
PRE_BYTES[2:0]
Data field
Mandatory
≥ 1 byte
SYNC_WORD_SIZE[1:0]
CRC
Optional
2 bytes
CRC_ON
Table 16. Data packet format
Optional 8/10 coding
Legend:
Optional CRC-16 calculation
Data f ield
CRC-16
32 bits
Sync word
Preamble bits
(1010...1010)
Inserted automatically in TX,
processed and remov ed in RX.
16/32 bits
8 x n bits
16 bits
Unprocessed user data
Figure 11. Packet format details (with recommended lengths of preamble and
synchronization word)
SWRS042A
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CC2400
23.3 Hardware interface
In the buffered mode the PKT pin can be
used as an interrupt output to assist the
microcontroller
in
supervising
the
transmission and reception of data
packets.
The PKT pin can be programmed to give
an interrupt when the synthesizer has
locked and is ready to receive / transmit a
data packet. Receive mode or transmit
mode can then be activated.
In receive mode there will be an interrupt
when the synchronization word is found.
Incoming data will then be written to the
FIFO.
In transmit mode there will be an interrupt
when the FIFO has run empty, the two
CRC bytes have been transmitted and the
transmitter has been turned off.
Outside of the TX and RX modes, the PKT
pin provides an indication of whether the
PLL is in lock or not. For example, in the
FSON state, the PKT pin will be high if the
PLL is in lock.
The PKT pin activity is illustrated in Figure
10.
The polarity of the interrupt signal is set by
the INT.PKT_POLARITY bit.
In transmit mode, the PKT pin will go low
for a short while when the transmission is
completely over (the CRC has been sent).
In receive mode, the PKT pin will go low
when a sync word is found. It will stay low
for the period of time it would take to
receive 32 bytes, no matter how long the
received packet is (the CC2400 does not
know how long incoming packets are).
24 Data / Line Encoding
The CC2400 can operate with the following
line-encoding formats:
• NRZ (Non-Return-to-Zero)
• Manchester coding (also known
as bi-phase-level)
• 8/10 coding
The data format is controlled by the
GRMDM.DATA_FORMAT[1:0]
bits.
Manchester coding and 8/10 coding
reduce the effective bit rate but are in
some applications used for spectral
properties and error detection.
Manchester coding means coding each bit
into two chips of opposite polarity. The
Manchester code is based on transitions;
a “0” is encoded as a low-to-high
transition, a “1” is encoded as a high-tolow transition. See Figure 14. The
Manchester code ensures that the signal
has a constant DC component, which is
necessary in some FSK demodulators.
This is not required by the CC2400
demodulator, but the coding option is
included for compatibility reasons. The
effective bit rate is half the baud rate using
Manchester coding.
8/10 coding means that 8 bits are coded
into 10 chips using the original IBM
8B/10B-coding scheme. The effective bit
rate is 80 % of the baud rate using 8/10
coding and is therefore more efficient that
the Manchester coding.
The benefit of the Manchester coding and
8/10 coding is the whitening of the
transmission spectrum even when rows of
equal bits are to be transmitted, improved
clock recovery properties and DC balance.
Setting the MDMTST0.INVERT_DATA bit
the data is inverted before transmission in
TX mode and inverted after reception in
RX mode.
24.1 Data encoding in buffered mode
In the buffered mode, using the internal
FIFO, all three line-encoding schemes can
be used.
The encoding/decoding takes place as the
data is sent from the FIFO to the
modulator, and from the demodulator to
the FIFO. The line encoding is therefore
invisible to the user.
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CC2400
If 8/10 coding is selected when using the
packet mode support, it should be noted
that the preamble and the sync words are
not encoded.
24.2 Data encoding in un-buffered
mode
When data buffering is not used, but the
DIO/DCLK interface, the CC2400 can be
configured for two different data formats:
Synchronous NRZ mode. In transmit
mode CC2400 provides the data clock at
DCLK, and DIO is used as data input.
Data is clocked into CC2400 at the rising
edge of DCLK. The data is modulated at
RF without encoding. In receive mode
CC2400 does the synchronization and
provides received data clock at DCLK and
data at DIO. The data should be clocked
into the interfacing circuit at the rising
edge of DCLK. See Figure 12.
Synchronous Manchester encoded mode.
In transmit mode CC2400 provides the data
clock at DCLK, and DIO is used as data
input. Data is clocked into CC2400 at the
rising edge of DCLK and should be in NRZ
format. The data is modulated at RF with
Manchester code. The encoding is done
by CC2400. In this mode the effective bit
rate is half the baud rate due to the
coding. This limits the maximum bit rate to
500 kbps. In receive mode CC2400 does
the synchronization and provides received
data clock at DCLK and data at DIO.
CC2400 does the decoding and NRZ data
is presented at DIO. The data should be
clocked into the interfacing circuit at the
rising edge of DCLK. See Figure 13.
Transmitter side:
DCLK
Clock provided by
CC2400
DIO
Data provided by microcontroller (NRZ)
“RF”
FSK modulating signal (NRZ),
internal in CC2400
Receiver side:
“RF”
Demodulated signal (NRZ),
internal in CC2400
DCLK
Clock provided by
CC2400
DIO
Data provided by CC2400 (NRZ)
Figure 12. Synchronous NRZ mode
SWRS042A
Page 32 of 83
CC2400
Transmitter side:
DCLK
Clock provided by
CC2400
DIO
Data provided by microcontroller (NRZ)
“RF”
FSK modulating signal (Manchester encoded),
internal in CC2400
Receiver side:
“RF”
Demodulated signal (Manchester encoded),
internal in CC2400
DCLK
Clock provided by
CC2400
DIO
Data provided by CC2400 (NRZ)
Figure 13. Synchronous Manchester encoded mode
10110001101
TX
data
Time
Figure 14. Manchester encoding
SWRS042A
Page 33 of 83
CC2400
25 Radio control state machine
CC2400 has a built-in state machine that is
used to switch between different operation
states (modes). The change of state is
done either by writing to command strobe
registers, or using dedicated pins.
Before using the radio in either RX or TX
mode, the main crystal oscillator must be
turned on and become stable. The crystal
oscillator has a start-up time given in
Table 8, during which its output is gated
internally to avoid timing problems
stemming from too narrow clock pulses.
The crystal oscillator is controlled by
accessing
the
SXOSCON/SXOSCOFF
command
strobe
registers.
The
XOSC16M_STABLE bit in the status
register returned during address transfer
indicates whether the oscillator is running
and stable or not (See Table 13). This
status register can be polled when waiting
for the oscillator to start.
The frequency synthesizer (FS) can be
started by either accessing the command
strobe register SFSON or by using the RX
and TX control pins. The FS will then enter
its self-calibration mode. After the
calibration is performed, the FS needs to
lock onto the right LO frequency. The
calibration and lock acquisition time is
given in Table 8.
command strobe registers, or by using the
RX and TX control pins. It is possible to
change quickly between TX and RX by
way of the FS On state.
Turning off RF can be accomplished by
either accessing the command strobe
register SRFOFF or by using the RX and
TX control pins. When using the RX and
TX pins to go from the FS On to Radio Off
it is important that TX is set to 0 before RX
is set to 0.
The state transitions using the RX and TX
pins are illustrated in Figure 15.
Note that to switch between RX and TX,
the FSDIV register must be updated. This
is because direct conversion is used in TX
mode, while an IF frequency of 1 MHz is
used in RX mode. Please see page 47 for
more
information
about
frequency
programming.
Also note that the FSDIV register should
only be changed when the radio is in IDLE
mode, otherwise the PLL can go out of
lock.
When the FS is in lock it is possible to go
into RX or TX mode. That can be done
either by accessing the SRX/STX
SWRS042A
Page 34 of 83
CC2400
OFF
[0]
SXOSCOFF
SXOSCON &
Osc. settled
IDLE
[1]
RX=TX=1
SRX | STX | SFSON
PIN
RXTX_CAL
[8]
STROBE
RXTX_CAL
[14]
All calib done &
fs in lock
All calib done &
fs in lock
PIN
FS_ON
[9]
RX=TX=0 |
RX=TX=1
RX=0
TX=0 |
STX
RX=TX=0 |
RX=TX=1
RX=TX=0
PIN
TX
[12]
PIN
RX
[10]
STROBE
TX
[17]
TX=1 |
RX=0 | packet done
SFSON | packet done
SRX
STROBE
RX
[16]
SRFOFF|
SFSON | packet
done
RX=1 | packet done
PIN
TX_OFF
[13]
STROBE
FS_ON
[15]
SFSON
TX=0
PIN
RX_OFF
[11]
STROBE
TX_OFF
[18]
Immediately
SRFOFF
BEFORE_IDLE
[24]
Figure 15. Radio control state diagram (FSMSTATE.FSM_CUR_STATE[4:0] value in
brackets)
Figure 15 shows a state transition diagram
for the radio control state machine. This
figure shows the possibilities that exist for
changing between states. Note for
example that it is not possible to go from
IDLE mode back to OFF. This diagram
can be very useful for debugging what is
happening within the CC2400 by reading
FSMSTATE.FSM_CUR_STATE[4:0].
If invalid parameters are used during
development or testing, the PLL may not
lock after calibration. If this happens, the
CC2400 will get stuck in the
STROBE_RXTX_CAL state. The chip
must then be reset to exit this state. This
should never happen in an actual
application as long as recommended
register settings are used.
Also note that the frequency register
FSDIV should only be modified when the
CC2400 is in IDLE mode, otherwise the
PLL may go out of lock since calibration is
only performed when exiting the IDLE
state
SWRS042A
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CC2400
26 Power Management Flow Chart
CC2400 offers great flexibility for power
with very low power consumption and the
crystal oscillator is not running.
management in order to meet strict power
consumption requirements in batteryoperated applications.
Figure 17 shows the sequence for
entering RX or TX mode. The flow chart
illustrates the simplest way to send a data
packet using the strobe command
registers. After one or more data packets
are transmitted or received, the chip is
again set to Power Down mode.
After reset the CC2400 is in Power Down
mode. All configuration registers can then
be programmed in order to make the chip
ready to operate at the correct frequency,
data rate and mode. Due to the very fast
start-up time, the CC2400 can remain in
Power Down until a transmission session
is requested.
During chip initialization a few registers
need to be programmed to other values
than their reset values. SmartRF® Studio
should be used to find/generate the
required configuration data for these
registers.
Figure 16 shows a typical power-on and
initializing sequence. After this initializing
sequence the chip is in Power Down mode
Power off
Supply power turned on
Reset:
MAIN = 0x0000
MAIN = 0x8000
Program all registers that are
different from reset value
Power Down
Figure 16. Initializing sequence
SWRS042A
Page 36 of 83
CC2400
PD
(Power Down)
SXOSCON
Wait until crystal oscillator is
stable
Wait for the specified crystal
oscillator start-up time, or poll the
XOSC16M_STABLE bit
IDLE
(XOSC is running)
SFSON
The PLL and filters are
calibrated
FSON
(XOSC and PLL is running)
RX: SRX
RX or TX?
TX
Write data to FIFO
TX: STX
Data is received. FIFO should
be read if buffered mode is
used
NO: SFSON
Go to
power
down?*
Data is transmitted. FIFO
should be filled if buffered
mode is used
YES: SXOSCOFF
YES: SXOSCOFF
Go to
power
down?*
NO: SFSON
NO: SRFOFF
NO: SRFOFF
Power Down
*Go to PD state if the crystal oscillator
should be shut off in order to save
power. Go back to IDLE if a new
packet shall be received/transmitted
quickly. Or go back to FSON if
changing fast between RX and TX
mode.
Figure 17. Sequence for activating RX or TX mode
SWRS042A
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CC2400
27 FSK Modulation Formats
The data modulator can modulate 2FSK,
which is two level FSK, and GFSK, which
is a Gaussian filtered FSK with BT=0.5 at
1 Mbps (for lower data rates BT will be
higher).
The purpose of the GFSK is to make a
more bandwidth efficient system. The
modulation and the Gaussian filtering is
performed
internally.
The
GRMDM.TX_GAUSSIAN_FILTER
bit
enables the GFSK.
However, if GFSK modulation is used
together with a data rate of 1 Mbps, it is
recommended to use a preamble length of
32 bytes as otherwise packet error
performance can be affected.
Figure 18 shows a plot of the spectrum for
FSK and GFSK modulation. Input data
was a PN9 sequence. The plot was
captured using a spectrum analyzer set to
5 MHz span and 300 kHz RBW.
0
-10
Power (dBm)
-20
-30
FSK
GFSK
-40
-50
-60
-70
2,438
2,439
2,440
2,441
2,442
2,443
Frequency [GHz]
Figure 18. Modulated spectrum
28 Built-in Test Pattern Generator
The CC2400 has a built-in test pattern
generator that can generate a PN9
pseudo
random
sequence.
The
MDMTST0.TX_PRNG bit enables the PN9
generator.
The PN9 generator can be used for
transmission of ‘real-life’ data when
measuring modulation bandwidth or
occupied bandwidth.
The PN9 pseudo random sequence is
defined by the polynomial x9 + x5 + 1.
SWRS042A
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CC2400
29 Receiver Channel Bandwidth
In order to meet different channel width
and channel spacing requirements, the
receiver’s digital channel filter bandwidth
is programmable. It can be programmed
from 125 to 1000 kHz.
The GRDEC.CHANNEL_DEC[1:0] register
bits control the bandwidth.
The table below summarizes
selectable channel bandwidths.
Channel filter
bandwidth
[kHz]
1000
500
250
125
the
GRDEC.CHANNEL_DEC[1:0]
[binary]
There is a tradeoff between selectivity and
accepted
frequency
tolerance.
In
applications where larger frequency drift is
expected (depends on the accuracy of the
crystal), the filter bandwidth should be
increased, at the expense of reduced
adjacent channel rejection (ACR).
It is strongly recommended to use one of
the three settings for over-the-air data
rates and channel bandwidths as
described in the section “Data Rate
Programming” on page 40.
00
01
10
11
SWRS042A
Page 39 of 83
CC2400
30 Data Rate Programming
The supported over-the-air data rates are
1Mbps, 250kbps and 10kbps. The data
rate is programmable via the GRDEC
register.
CHANNEL
_DEC
[binary]
00
00
01
Supported channel filter bandwidths and
data rates are shown in the following
table.
DEC_
VAL
BW
[kHz]
Data rate
[kbps]
[decimal]
0
3
49
1000
1000
500
1000
250
10
Figure 19 shows how sensitivity varies as
a function of frequency offset between the
transmitter and the receiver for various
data rates. It is possible to tolerate even
larger offsets by making use of the AFC
feature; please see page 42 for further
details.
-10
-50
250 kbps
1 Mbps
10 kbps
-70
-90
420
390
360
330
300
270
240
210
180
150
90
120
60
0
30
-30
-60
-90
-120
-150
-180
-210
-240
-270
-300
-330
-360
-390
-420
-110
-450
Sensitivity (dBm)
-30
Offset (kHz)
Figure 19. Sensitivity as a function of frequency offset
SWRS042A
Page 40 of 83
CC2400
31 Demodulator, Bit Synchronizer and Data Decision
The block diagram for the demodulator,
data slicer and bit synchronizer is shown
in Figure 20. The built-in bit synchronizer
extracts the data rate and performs data
decision. The data decision is done using
over-sampling and digital filtering of the
incoming signal. This improves the
reliability of the data transmission and
provides a synchronous clock in the unbuffered mode. Using the buffered mode
simplifies the data interface further, as
data can be written and read byte-for-byte
in bursts from the FIFO.
The suggested preamble is a 32 bit
‘(0)10101…’ bit pattern, the same as used
by the packet handling support, see page
29. This is necessary for the bit
synchronizer to synchronize with the
coding correctly.
The data slicer performs the bit decision.
Ideally the two received FSK frequencies
are placed symmetrically around the IF
frequency. However, if there is some
frequency error between the transmitter
and the receiver, the bit decision level
should be adjusted accordingly. In CC2400
this is done automatically by measuring
the two frequencies and by using the
average value as the decision level.
The digital data slicer in CC2400 uses an
average value of the minimum and
maximum frequency deviation detected as
the
comparison
level.
The
MDMTST0.AFC_DELTA register is used to
set the expected deviation of the incoming
signal. Once a shift in the received
frequency larger than half the expected
separation is detected, a bit transition is
recorded and the average value to be
used by the data slicer is calculated.
The actual number of samples used to find
the averaging value can be programmed
and set higher for better data decision
accuracy. This is controlled by the
AFC_SETTLING[1:0] bits. If RX data is
present in the channel when the RX chain
is turned on, then the data slicing estimate
will usually give correct results after 4 bits.
The data slicing accuracy will increase
after
this,
depending
on
the
AFC_SETTLING[1:0] bits. If the start of
a transmission occurs after the RX chain
is turned on, the minimum number of bit
transitions (or preamble bits) before
correct data slicing will depend on the
AFC_SETTLING[1:0] bits, as shown in
Table 17. The recommended setting is
11b, requiring 16 data bits of preamble to
fill the averaging filter completely.
The internally calculated average FSK
frequency value gives a measure for the
frequency offset of the receiver compared
to the transmitter. The frequency offset
can
be
read
from
RSSI.RX_FREQ_OFFSET[7:0].
This
information can also be used for an
automatic frequency control, as described
at page 43.
Average
filter
Digital IF
filtering
Frequency
detector
Decimator
Data
filter
Data slicer
comparator
Bit
synchronizer
and data
decoder
Figure 20. Demodulator block diagram
SWRS042A
Page 41 of 83
CC2400
AFC settling time
MDMTST0.AFC_SETTLING[1:0]
# Bits
00
01
10
11
2
4
8
16
Table 17. Minimum number of bits for the averaging filter
32 Automatic Frequency Control
CC2400 has a built-in optional feature
called
AFC
(Automatic
Frequency
Control). This feature can be used to
measure and compensate for frequency
drift.
The average frequency offset of the
received signal (from the nominal IF) can
be
read
from
the
FREQEST.RX_FREQ_OFFSET[7:0]
register. This is a signed (2’s-complement)
8-bit value that can be used to
compensate for frequency offset between
an external transmitter and the receiving
device. The frequency offset is given by:
∆F= RX_FREQ_OFFSET x 5.2
this feature please refer to page 53
(Crystal drift compensation).
Figure 21 shows how the value of the
FREQEST.RX_FREQ_OFFSET[7:0]
register varies as a function of frequency
offset
for
different
values
of
MDMTST0.AFC_SETTLING[1:0].
Chipcon recommends using a value of 4.
The following procedure should be
followed when using the AFC to
compensate for a frequency offset
between transmitter and receiver:
1. Read
the
FREQEST.RX_FREQ_OFFSET[7:
0] register. This is a signed 2’scomplement value.
2. Use the equation on this page to
calculate the frequency offset in
kHz.
3. The microcontroller then needs to
calculate the equivalent value to
write
to
the
MDMCTRL.MOD_OFFSET[5:0]
register.
[kHz]
The receiver can be calibrated against an
external transmitter (another CC2400 or an
external test signal) by changing the
operating frequency according to the
measured offset. The new frequency must
be calculated by the microcontroller and
written
to
the
MDMCTRL.MOD_OFFSET[5:0]
register.
After this compensation the center
frequency of the received signal will better
match the digital channel filter bandwidth.
The compensation, as described above,
also automatically compensates the
transmitter, i.e. the transmitted signal will
match the ‘external’ transmitter’s signal.
However, compensating the transmitter
signal may cause additional spurs in the
TX
spectrum.
Chipcon
therefore
recommends only compensating in RX
mode.
This feature reduces the requirement on
the crystal accuracy, which is important
when using the narrower channel
bandwidths. For a further description of
For example:
The value read from the
FREQEST.RX_FREQ_OFFSET[7:0]
register is 0xE0. This equals –32 since the
register value is in signed 2’s complement.
This corresponds to –32 x 5.2 = -166.4
kHz.
The MOD_OFFSET register should
therefore be set to –166.4 kHz / 15.625
kHz = -10.6496 ≈ -11. –11 equals 0x35 in
hexadecimal.
SWRS042A
Page 42 of 83
CC2400
100
80
60
40
AFC value
20
0
-500 -450 -400 -350 -300 -250 -200 -150 -100 -50
AFC with settle = 8
AFC with settle = 4
0
50
100 150 200 250 300 350 400 450 500 550
AFC with settle = 2
AFC with settle = 1
-20
-40
-60
-80
-100
Frequency offset [kHz]
Figure 21. AFC value vs. frequency offset
33 Linear IF and AGC Settings
CC2400 is based on a linear IF chain
where the signal amplification is done in
an analog VGA (variable gain amplifier).
The gain of the VGA is controlled by the
digital part of the IF-chain after the ADC
(Analog Digital Converter).
The AGC (Automatic Gain Control) loop
ensures that the ADC operates inside its
dynamic range by using an analog/digital
feedback loop.
The AGC characteristics are set through
the AGCCTRL, AGCTST0, AGCTST1 and
AGCTST2 registers.
Note that the RSSI function does not take
AGC settings into consideration if the AGC
settings are overridden.
SWRS042A
Page 43 of 83
CC2400
34 RSSI
CC2400 has a built-in RSSI (Received
Signal Strength Indicator) giving a digital
value that can be read form the
RSSI.RSSI_VAL[7:0] register.
The RSSI reading provides a measure of
the signal power entering the RF input.
The scale is logarithmic, so that
RSSI_VAL provides a value in dB.
The RSSI measurement can be referred to
the power at the RF input pins by using
the following equation:
P = RSSI_VAL + RSSI_OFFSET [dBm]
where
the
nominal
value
of
RSSI_OFFSET is –54dB. (If the gain in
the LNA/Mixer is changed from the default
settings, the offset is changed.)
The number of samples that are used to
calculate the average signal amplitude is
controlled
by
the
RSSI.RSSI_FILT[1:0] register. The
RSSI filter length (averaging) can be done
over up to 8 symbols. This will determine
the response time of the RSSI.
A typical plot of the RSSI_VAL reading as
function of input power is shown in Figure
22 (for 1Mbps).
Note that the RSSI function does not take
AGC settings into consideration if the AGC
settings are overridden.
50
40
30
20
0
1M
250kb
10kb
-10
-20
-30
-40
-50
0
-4
-8
-60
-1
20
-1
16
-1
12
-1
08
-1
04
-1
00
-9
6
-9
2
-8
8
-8
4
-8
0
-7
6
-7
2
-6
8
-6
4
-6
0
-5
6
-5
2
-4
8
-4
4
-4
0
-3
6
-3
2
-2
8
-2
4
-2
0
-1
6
-1
2
RSSI
10
Input level (dBm)
Figure 22. Typical RSSI value vs. input power
SWRS042A
Page 44 of 83
CC2400
35 Carrier Sense
to a threshold of –70 dBm. A threshold of
0x09 corresponds to –18 dBm, and a
threshold of 0x37 corresponds to –90
dBm.
The carrier sense signal is based on the
measured
RSSI
value
and
a
programmable threshold. The carriersense function can be used to simplify the
implementation of a CSMA (Carrier Sense
Multiple Access) medium access protocol.
The carrier sense signal can be
multiplexed to the GIO1/GIO6 pin. The
CARRIER_SENSE_N signal is enabled by
setting
IOCFG.GIO1_CFG[5:0]
=
01010B (see Table 18).
Carrier
sense
threshold
level
is
programmed
by
RSSI.RSSI_CS_THRES[5:0].
The
value of this register can be calculated in
the same way as described for
RSSI.RSSI_VAL in the previous section,
except that the unit is 4 dB instead of 1
dB. The default level (0x3C) corresponds
36 Interfacing an External LNA or PA
CC2400 has two digital output pins, GIO1
and GIO6, which can be used to control
an external LNA or PA. The functionality of
these pins are controlled through the
IOCFG register.
The PA_EN, PA_EN_N, RX_PD, TX_PD
signals can be multiplexed to the
GIO1/GIO6 pin and used for controlling
the PA / LNA and one or more T/R
switches.
These two pins can also be used as two
general control signals, see Table 18.
For further information on attaching a PA,
please see page 54.
37 General Purpose / Test Output Control Pins
The two digital output pins, GIO1 and
GIO6, can be used as two general control
signals
by
writing
to
IOCFG.GIO1_CFG[5:0]
and
IOCFG.GIO6_CFG[5:0].
GIO1_CFG = 61 sets the pin low, and
GIO1_CFG = 62 sets the pin high.
This feature can be used to save I/O pins
on the microcontroller when the other
functions associated with these pins are
not used.
These two pins can also be used as a test
pin to monitor a lot of internal signals. This
is summarized in Table 18.
Signal
I/O
Description
[decimal]
0
1
2
3
4
5
Reserved
Reserved
Reserved
PA_EN
PA_EN_N
SYNC_RECEIVED
O
O
O
O
O
O
6
7
8
9
PKT
Reserved
Reserved
Reserved
O
I
O
O
Reserved
Reserved
Reserved
Active high PA enable signal
Active low PA enable signal
Set if a valid sync word has been received since last
time RX was turned on
Packet status signal See Figure 10, page 28.
Reserved
Reserved
Reserved
GIO1_CFG /
GIO6_CFG
SWRS042A
Page 45 of 83
CC2400
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
26
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
CARRIER_SENSE_N
CRC_OK
AGC_EN
FS_PD
RX_PD
TX_PD
Reserved
Reserved
Reserved
Reserved
Reserved
Reserved
PKT_ACTIVE
MDM_TX_DIN
MDM_TX_DCLK
MDM_RX_DOUT
MDM_RX_DCLK
MDM_RX_BIT_RAW
Reserved
MDM_BACKEND_EN
MDM_DEC_OVRFLW
AGC_CHANGE
VGA_RESET_N
CAL_RUNNING
SETTLING_RUNNING
RXBPF_CAL_RUNNING
VCO_CAL_START
RXBPF_CAL_START
FIFO_EMPTY
FIFO_FULL
CLKEN_FS_DIG
CLKEN_RXBPF_CAL
CLKEN_GR
XOSC16M_STABLE
XOSC_16M_EN
XOSC_16M
CLK_16M
CLK_16M_MOD
CLK_8M16M_FSDIG
CLK_8M
CLK_8M_DEMOD_AGC
Reserved
Reserved
FREF
FPLL
PD_F_COMP
WINDOW
LOCK_INSTANT
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
58
59
60
61
62
63
RESET_N_SYSTEM
FIFO_FLUSH
LOCK_STATUS
ZERO
ONE
HIGH_Z
O
O
O
O
O
-
Carrier sense output (RSSI above threshold)
CRC check OK after last byte read from FIFO
AGC enable signal
Frequency synthesiser power down
RX power down
TX power down
Reserved
Reserved
Reserved
Reserved
Reserved
Reserved
Packet reception active
The TX data sent to modem
The TX clock used by modem
The RX data received by modem
The RX clock recovered by modem
The un-synchronized RX data received by modem
Reserved
The Backend enable signal used by modem in RX
Modem decimation overflow
Signal that toggles whenever AGC changes gain.
The VGA peak detectors' reset signal
VCO calibration in progress
Stepping CHP current after calibration
RX band-pass filter calibration running
VCO calibration start signal
RX band-pass filter start signal
FIFO empty signal
FIFO full signal
Clock enable Frequency Synthesiser
Clock enable RX band-pass filter calibration
Clock enable generic radio
Indicates that the Main crystal oscillator is stable
16 MHz XOSC enable signal
16 MHz XOSC output from analog part
16 MHz clock from main clock tree
16 MHz modulator clock tree
8/16 MHz clock tree for fs_dig module
8 MHz clock tree derived from XOSC_16M
8 MHz clock tree for demodulator/AGC
Reserved
Reserved
Reference clock (4 MHz)
Output clock of A/M-counter (4 MHz)
Phase detector comparator output
Window signal to PD (Phase Detector)
Window signal latched in PD (Phase Detector) by the
FREF clock
Chip wide reset (except registers)
FIFO flush signal
The top-level FS in lock status signal
Output logic zero
Output logic one
Pin set as high-impedance output
Table 18. GIO1 / GIO6 signal select table
SWRS042A
Page 46 of 83
CC2400
38 Frequency Programming
The operating frequency is set by
programming the frequency word in the
FSDIV configuration register.
f0 = fc − fdev
f1 = fc + fdev
The frequency word is 12 bits and is
located
in
FSDIV.FREQ[11:0].
Writing/reading FSDIV[11:0] will give
the frequency directly in MHz. (The bits
FSDIV.FREQ[11:10] are hardwired to
‘10’ giving a fixed offset of 2048.)
where fdev is the FSK frequency deviation.
fdev
is
programmed
with
MDMCTRL.MOD_DEV[6:0] and given by
(in kHz):
FSDIV should only be modified while the
CC2400 is in IDLE mode. Otherwise the
PLL may go out of lock as a calibration is
only performed when exiting IDLE mode.
The default value is MOD_DEV = 64 giving
250 kHz deviation.
38.1 Transmit mode
In transmit mode an I/Q direct
upconversion scheme is used (i.e. no
intermediate frequency for the modulated
baseband
signal).
MDMTST0.TX_1MHZ_OFFSET_N=1 must
therefore be set during the chip
initialization sequence (ref. Figure 16).
When MDMTST0.TX_1MHZ_OFFSET_N=1
the transmit channel center frequency
(carrier frequency), fc, in MHz is given
directly by:
f c = FREQ[11:0] = 2048 + FREQ[9:0]
f dev = ±3.9062 ⋅ MOD _ DEV [6 : 0]
The TX_GAUSSIAN_FILTER bit in the
GRMDM register controls the Gaussian
shaping of the modulation signal. See also
page 38.
38.2 Receive mode
Low side LO injection is used, hence:
fLO = fRF − fIF
where, fRF is the center frequency of the
channel and fIF = 1 MHz.
Thus, in receive mode the frequency
generated by the frequency synthesizer,
fc, must be programmed to be the LO
frequency.
The two FSK modulation frequencies are
given by:
39 Alternate TX IF setting
It is possible to configure CC2400 to
operate with an intermediate frequency of
1 MHz in transmit mode. It is not generally
recommended to do this, as the TX
spectrum will have higher spur content
than when using the direct up conversion
mode. Using an intermediate frequency of
1 MHz in TX has the advantage of much
lower RX/TX switching time because the
VCO operates at the same frequency in
RX and TX.
1 MHz IF in TX mode is enabled by setting
MDMTST0.TX_1MHZ_OFFSET_N=0.
SWRS042A
Page 47 of 83
CC2400
40 VCO
The VCO is completely integrated and
operates at 4800 – 4966 MHz. The VCO
frequency is divided by 2 to generate
frequencies in the desired band (24002483 MHz).
The VCO frequency is related
FSDIV.FREQ[9:0] as follows:
to
f VCO = 2 ⋅ (2047 + FREQ[9 : 0])
41 VCO Self-Calibration
The characteristics of the VCO will vary
with temperature, changes in supply
voltages, and the desired operating
frequency. In order to ensure reliable
operation the bias current and tuning
range of the VCO are automatically
calibrated every time the RX mode or TX
mode is enabled.
42 Output Power Programming
The RF output power from the device is
programmable and is controlled by the
FREND.PA_LEVEL[2:0] register. Table
19 shows the relationship between the
PA_LEVEL[2:0]
[binary]
000
001
010
011
100
101
110
111
register value, output power and current
consumption.
RF frequency 2.45 GHz
Output power
Current
[dBm]
consumption,
typ. [mA]
-25
-15
-10
-7
-4.6
-2.8
-1.3
0
11
12
13
14
16
17
18
19
Table 19. Output power settings and typical current consumption
SWRS042A
Page 48 of 83
CC2400
43 Crystal Oscillator
An external clock signal or the internal
crystal oscillator can be used as main
frequency reference. The reference
frequency must be 16 MHz. Because the
crystal frequency is used as reference for
the data rate as well as other internal
signal
processing
functions,
other
frequencies cannot be used.
The crystal oscillator circuit is shown in
Figure 23. Typical component values for
different values of CL are given in Table
20. Note that these values will depend on
the PCB layout and the crystal used.
Determination of the values should be
done by measuring RF frequency on
several boards and adjusting the values of
the loading capacitors accordingly.
If an external clock signal is used this
should be connected to XOSC16_Q1,
while XOSC16_Q2 should be left open. If
rail-to-rail (1.8V) square-wave signal is
used, the MAIN.XOSC16M_BYPASS bit
must be set. It is also possible to use a
sine-wave input. A voltage swing of 200
mV peak-to-peak is recommended in this
case.
The crystal oscillator is amplitude
regulated. This means that a high current
is used to start up the oscillations. When
the amplitude builds up, the current is
reduced to what is necessary to maintain
a stable oscillation. This ensures a fast
start-up and keeps the drive level to a
minimum. The ESR of the crystal should
be within the specification in order to
ensure a reliable start-up (see the
Electrical Specifications section).
Using the internal crystal oscillator, the
crystal must be connected between the
XOSC16_Q1 and XOSC16_Q2 pins. The
oscillator is designed for parallel mode
operation of the crystal. In addition,
loading capacitors (C5 and C6) for the
crystal are required. The loading capacitor
values depend on the total load
capacitance, CL, specified for the crystal.
The total load capacitance seen between
the crystal terminals should equal CL for
the crystal to oscillate at the specified
frequency.
1
CL =
+ C parasitic
1
1
+
C 421 C 431
The parasitic capacitance is constituted by
pin input capacitance and PCB stray
capacitance.
The
total
parasitic
capacitance is typically 5 pF.
A small SMD crystal is used in the
reference design; note that the crystal
package strongly influences the price. In a
low-cost design, it may be preferable to
use a larger crystal package.
The required accuracy of the crystal is
determined by the receive filtering. Figure
19 shows how sensitivity varies with the
frequency offset between the transmitter
and the receiver. It is important to take the
total tolerance of the crystal into
consideration; this consists of the initial
tolerance, drift due to temperature and
aging.
XOSC16_Q1
XOSC16_Q2
XTA L
C421
C431
Figure 23. Crystal oscillator circuit
Item
CL= 16 pF
C421
C431
22 pF
22 pF
SWRS042A
Page 49 of 83
CC2400
Table 20. 16MHz crystal oscillator component values for CL=16pF
44 Input / Output Matching
The RF input / output is differential (RF_N
and RF_P). In addition there is supply
switch output pin (TXRX_SWITCH) that
must have an external DC path to RF_N
and RF_P.
In RX mode the TXRX_SWITCH pin is at
ground and will bias the LNA. In TX mode
the TXRX_SWITCH pin is at supply rail
voltage and will properly bias the internal
PA.
Application circuits are shown in Figure 3
and Figure 4. Component values are given
in Table 11.
If a single ended output is required (for a
single ended connector or a single ended
antenna), a balun should be used. The
balun can be realized using discrete
inductors and capacitors.
Using a differential antenna, no balun is
required.
The RF output and DC bias can be
achieved using different topologies.
45 Typical performance graphs
The following graphs show how some
important
parameters
vary
with
temperature. These graphs show typical
performance as a function of temperature,
and should be used as design guidance
only.
25
24
23
22
Current (mA)
21
RX Current
20
TX Current
19
18
17
16
15
-40
-20
0
20
40
60
80
Temp (deg C)
Figure 24 Typical RX and TX current vs. temperature
SWRS042A
Page 50 of 83
CC2400
30
25
Current (uA)
20
15
10
5
0
-40
-35
-30
-25
-20
-15
-10
-5
0
5
10
15
20
25
30
35
40
45
50
55
60
65
70
75
80
85
Temp (deg C)
Figure 25 Typical power-down current vs. temperature
5
4
3
2
Power (dBm)
1
0
-1
-2
-3
-4
-5
-6
-40
-20
0
20
40
60
80
Temp (deg C)
Figure 26 Typical output power vs. temperature
SWRS042A
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CC2400
-78
-80
Sensitivity (dBm)
-82
-84
-86
-88
-90
-92
-40
-15
10
35
60
85
Temperature (deg C)
Figure 27 Typical 1 Mbps sensitivity vs. temperature
SWRS042A
Page 52 of 83
CC2400
46 System Considerations and Guidelines
46.1 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 and EN 300 328 (Europe), FCC
CFR47 part 15.247 and 15.249 (USA),
and ARIB STD-T66 (Japan).
The
CC2400EM
reference
design
complies with EN 300 440. If frequency
hopping is to be used at 1 Mbps data rate,
GFSK should be selected to keep the
bandwidth below 1 MHz. The CC2400
complies with EN 300 440 class 2 if the
band spacing is 2 MHz or more. It
complies with EN 300 440 class 1 if the
channel and band spacing is 10 MHz or
more.
Please note that compliance with
regulations is dependent on complete
system performance. It is the customer’s
responsibility to ensure that the system
complies with regulations.
46.2 Frequency hopping and multichannel 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 multichannel protocol because the frequency
diversity makes the system more robust
with respect to interference from other
systems operating in the same frequency
band.
CC2400 is highly suited for FHSS or multichannel 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 will significantly offload the host
controller.
Due to the low-IF I/Q receiver and the onchip complex filtering, the image channel
will be significantly rejected. This is
important for all 2.4GHz systems.
46.3 Data burst transmissions
The high maximum data rate of CC2400
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
1 Mbps) will reduce the time in active
mode, and hence also reduce the average
current consumption significantly.
46.4 Continuous transmissions
In data streaming applications the CC2400
opens up for continuous transmissions at
1 Mbps effective data rate. A typical
application is digital audio systems. As the
modulation is done with an I/Q 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.)
46.5 Crystal drift compensation
A unique feature in CC2400 is the very fine
frequency
resolution
using
the
MDMCTRL.MOD_OFFSET[5:0].
This
feature can be used to compensate for
frequency
offset
and
drift.
The
compensation affects both the receiver
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
programmability.
This
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 CC2400 and can be read back from
an
internal
register
(FREQEST.RX_FREQ_OFFSET[7:0]).
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Page 53 of 83
CC2400
The measured frequency offset can thus
be used to calibrate the frequency using
the ‘external’ transmitter as the reference.
See also page 42 (Automatic Frequency
Control).
Figure
28
shows
the
improvement that can be achieved.
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
be
used
without
further
compensation.
46.6 Spectrum efficient modulation
CC2400 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.
46.7 Low latency systems
CC2400 is ideal for applications where
latency is critical. Unbuffered mode should
be used for lowest latency, since it takes
time to fill the FIFO buffer. The total
latency over the RF link in unbuffered
mode is around 8 s. CC2400 can also
provide very low RX-TX switching time, as
described on page 47.
46.8 Low cost systems
As the CC2400 provides 1 Mbps multichannel 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 4.
A small SMD crystal is used in the
reference design; note that the crystal
package strongly influences the price. In a
low-cost design, it may be preferable to
use a larger crystal package.
46.9 Battery operated systems
In low power applications, the power down
mode should be used when not active.
Depending
on
the
start-up
time
requirement, the crystal oscillator core can
be powered during power down. See page
36 for information on how effective power
management can be implemented.
46.10 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 T/R switches are needed to
disconnect the PA in RX mode. See
Figure 29.
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CC2400
0
-10
-20
-30
Sensitivity (dBm)
-40
With mod_offset compensation
Without mod_offset compensat
-50
-60
-70
-80
-90
-100
-350
-300
-250
-200
-150
-100
-50
0
50
100
150
200
250
Frequency offset from center (kHz)
Figure 28. Sensitivity vs. frequency offset with and without AFC
Antenna
Filter
PA
CC2400
Balun
T/R switch
T/R switch
Figure 29. Block diagram of CC2400 usage with external power amplifier
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CC2400
47 PCB Layout Recommendations
A four layer PCB is highly recommended.
The second layer of the PCB should be
the “ground-layer”.
The top layer should be used for signal
routing, and the open areas should be
filled with metallization connected to
ground using several vias.
The area under the chip is used for
grounding and must be connected closely
to the ground plane with several vias.
The ground pins should be connected to
ground as close as possible to the
package pin using individual vias. The decoupling capacitors should also be placed
as close as possible to the supply pins
and connected to the ground plane by
separate vias. Supply power filtering is
very important.
The external components should be as
small as possible (0402 is recommended)
and surface mount devices must be used.
Please note that components smaller than
those specified may have differing
characteristics.
Caution should be used when placing the
microcontroller
in order
to avoid
interference with the RF circuitry.
A Development Kit with a fully assembled
Evaluation Module is available. It is
strongly advised that this reference layout
is followed very closely in order to achieve
the best performance.
The schematic, BOM and layout Gerber
files for the reference designs are all
available from the Chipcon website.
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CC2400
48 Antenna Considerations
CC2400 can be used together with various
types of antennas. A differential antenna
like a dipole would be the easiest to
interface not needing a balun (balanced to
un-balanced transformation network).
The length of the λ/2-dipole antenna is
given by:
L = 14250 / f
where f is in MHz, giving the length in cm.
An antenna for 2450 MHz should be 5.8
cm. Each arm is therefore 2.9 cm.
Other commonly used antennas for shortrange communication are monopole,
helical and loop antennas. The singleended monopole and helical would require
a balun network between the differential
output and the antenna.
Monopole
antennas
are
resonant
antennas with a length corresponding to
one quarter of the electrical wavelength
(λ/4). They are very easy to design and
can be implemented simply as a “piece of
wire” or even integrated into the PCB.
The length of the λ/4-monopole antenna is
given by:
L = 7125 / f
Non-resonant monopole antennas shorter
than λ/4 can also be used, but at the
expense of range. In size and cost critical
applications such an antenna may very
well be integrated into the PCB.
Enclosing the antenna in high dielectric
constant material reduces the overall size
of the antenna. Many vendors offer such
antennas intended for PCB mounting.
Helical antennas can be thought of as a
combination of a monopole and a loop
antenna. They are a good compromise in
size critical applications. But helical
antennas tend to be more difficult to
optimize than the simple monopole.
Loop antennas are easy to integrate into
the PCB, but are less effective due to
difficult impedance matching because of
their very low radiation resistance.
For low power applications the differential
antenna is recommended giving the best
range and because of its simplicity.
The antenna should be connected as
close as possible to the IC. If the antenna
is located away from the RF pins the
antenna should be matched to the feeding
transmission line (50 Ω).
where f is in MHz, giving the length in cm.
An antenna for 2450 MHz should be 2.9
cm.
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CC2400
49 Configuration Registers
The configuration of CC2400 is done by
programming the 16-bit configuration
registers. The configuration data based on
selected system parameters are most
easily found by using the SmartRF Studio
software. Complete descriptions of the
registers are given in the following tables.
After a RESET is programmed, all the
registers have default values as shown in
the tables.
Some registers are Strobe Command
Registers. Accessing these registers will
initiate the change of an internal state or
mode.
The FIFO is accessed as an 8-bit register.
Some registers contain signed values.
These are in two’s complement format. I.e.
for a 4-bit value, 0000 is 0, 1111 is –1,
1110 is –2, 1000 is -8 and 0111 is 7.
During the address transfer a status byte
is returned. This status byte is described
in Table 13 at page 23.
0x00
0x01
0x02
0x03
0x04
0x05
0x06
0x07
0x08
0x09
0x0A
0x0B
0x0C
0x0D
0x0E
0x0F
0x10
0x11
0x12
0x13
0x14
0x15
0x16
0x17
0x18
0x19
0x1A
0x1B
0x1C
0x1D
0x1E
0x1F
0x20
0x21
1
Register name
Register Type
Address
1
Overview of CC2400 ‘s control registers
MAIN
FSCTRL
FSDIV
MDMCTRL
AGCCTRL
FREND
RSSI
FREQEST
IOCFG
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
FSMTC
RESERVED
MANAND
FSMSTATE
ADCTST
RXBPFTST
PAMTST
LMTST
MANOR
MDMTST0
MDMTST1
DACTST
AGCTST0
AGCTST1
AGCTST2
FSTST0
FSTST1
FSTST2
FSTST3
MANFIDL
MANFIDH
GRMDM
GRDEC
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R
R
R/W
R/W
Description
Main control register
Frequency synthesiser main control and status
Frequency synthesiser frequency division control
Modem main control and status
AGC main control and status
Analog front-end control
RSSI information
Received signal frequency offset estimation
I/O configuration register
Unused
Unused
Finite state machine time constants
Reserved register containing spare control and status bits
Manual signal AND-override register
Finite state machine information and breakpoint
ADC test register
Receiver bandpass filters test register
PA and transmit mixers test register
LNA and receive mixers test register
Manual signal OR-override register
Modem test register 0
Modem test register 1
DAC test register
AGC test register: various control and status.
AGC test register: AGC timeout.
AGC test register: AGC various parameters.
Test register: VCO array results and override.
Test register: VC DAC manual control. VCO current constant.
Test register:VCO current result and override.
Test register: Charge pump current etc.
Manufacturer ID, lower 16 bit
Manufacturer ID, upper 16 bit
Generic radio modem control
Generic radio decimation control and status
R/W - Read/write (control/status), R - Status only, S – Strobe command register (perform action upon access)
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Register Type
Address
1
CC2400
Register name
Description
0x22
0x23
0x24
0x25
0x26
0x27
0x28
0x29
0x2A
0x2B
0x2C
0x2D
...
0x60
0x61
PKTSTATUS
INT
Reserved
Reserved
Reserved
Reserved
Reserved
Reserved
Reserved
Reserved
SYNCL
SYNCH
R
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
Packet mode status
Interrupt register
SXOSCON
SFSON
S
S
0x62
0x63
0x64
0x65
0x66
0x67
0x68
0x69
0x6A
0x6B
0x6C
0x6D
0x6E
0x6F
0x70
SRX
STX
SRFOFF
SXOSCOFF
Reserved
Reserved
Reserved
Reserved
Reserved
Reserved
Reserved
Reserved
Reserved
Reserved
FIFOREG
S
S
S
S
S
S
S
S
S
S
S
S
S
S
Special
Command strobe register: Turn on XOSC.
Command strobe register: Start and calibrate FS and go from RX/TX to a wait
mode where the FS is running.
Command strobe register: Start RX.
Command strobe register: Start TX (turn on PA).
Command strobe register: Turn off RX/TX and FS.
Command strobe register: Turn off XOSC.
Synchronisation word, lower 16 bit.
Synchronisation word, upper 16 bit.
Used to write data to and read data from the 8-bit wide 32 bytes FIFO used to
buffer outgoing TX data and incoming RX data in buffered RF mode.
MAIN (0x00) - Main Control Register
Field Name
Reset
R/W
Description
15
Bit
RESETN
-
R/W
Active low reset of entire circuit. Should be applied before doing
anything else.
14:10
-
0
W0
Reserved, write as 0.
9
FS_FORCE_EN
0
R/W
Forces the frequency synthesiser on (starts with a calibration).
The synthesiser can also be turned on in a number of other
ways.
8
RXN_TX
0
R/W
Selects whether RX operation ('0') or TX operation ('1') is desired
when FS_FORCE_EN is used. RX or TX mode is usually
selected using the SRX and STX strobe commands (or RX and
TX pins).
7:4
-
0
W0
Reserved, write as 0.
3
-
0
R/W
Reserved, write as 0.
2
-
0
R/W
Reserved, write as 0.
1
XOSC16M_BYPASS
0
R/W
Bypasses the 16 MHz main crystal oscillator and uses a buffered
version of the signal on Q1 directly. Used for external clock only.
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CC2400
Bit
0
Field Name
Reset
R/W
Description
XOSC16M_EN
0
R/W
Forces the 16 MHz main crystal oscillator and the global bias on.
These modules can also be turned on in other ways.
FSCTRL (0x01) - Frequency Synthesiser Control and Status
Bit
Field Name
Reset
R/W
Description
15:6
-
0
W0
Reserved, write as 0.
5:4
LOCK_THRESHOLD[1:0]
1
R/W
Number of consecutive reference clock periods with successful
sync windows required to indicate lock:
0: 64
1: 128
2: 256
3: 512
3
CAL_DONE
0
R
Calibration has been performed since the last time the FS was
turned on.
2
CAL_RUNNING
0
R
Calibration status, '1' when calibration in progress.
1
LOCK_LENGTH
0
R/W
LOCK_WINDOW pulse width:
0: 2 CLK_PRE periods
1: 4 CLK_PRE periods
0
LOCK_STATUS
0
R
'1' when PLL is in lock, otherwise '0'.
FSDIV (0x02) - Frequency Synthesiser Frequency Division Control
Field Name
Reset
R/W
Description
15:12
Bit
-
0
W0
Reserved, write as 0.
11:10
FREQ[11:10]
2
R
Read only.
Directly gives the right frequency in MHz when reading/writing
FREQ[11:0].
9:0
FREQ[9:0]
353
R/W
Frequency control word.
f c = FREQ[11 : 0] = 2048 + FREQ[9 : 0]
[MHz]
where fc is the channel centre frequency. See page 47 for a
description of how to program the channel for tansmit and
receive modes respectively.
Reading/writing FREQ[11:0] gives the right frequency in MHz.
The default value corresponds to fc=2401MHz.
MDMCTRL (0x03) - Modem Control and Status
Bit
Field Name
Reset
R/W
Description
15:13
-
0
W0
Reserved, write as 0.
12:7
MOD_OFFSET[5:0]
0
R/W
Modulator/Demodulator centre frequency in 15.625 kHz steps
(for the receiver the steps are relative to 1 MHz, for the
transmitter the steps are relative to 0MHz when
MDMTST0.TX_1MHZ_OFFSET_N=1).
Two's complement signed value. I.e. MOD_OFFSET=0x1F Î
centre frequency=1.48 MHz; MOD_OFFSET=0x20 Î centre
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CC2400
Bit
Field Name
Reset
R/W
Description
frequency=0.50 MHz.
6:0
MOD_DEV[6:0]
64
R/W
Modulator frequency deviation in 3.9062 kHz steps (0-500 kHz).
Unsigned value. Reset value gives a deviation of 250 kHz.
AGCCTRL (0x04) - AGC Control and Status
Field Name
Reset
R/W
Description
15:8
Bit
VGA_GAIN [7:0]
0XF7
R/W
When written, VGA manual gain override value; when read, the
currently used VGA gain setting.
7:4
-
0
W0
Reserved, write as 0.
3
AGC_LOCKED
0
R
AGC lock status
2
AGC_LOCK
0
R/W
Lock gain after maximum number of attempts.
1
AGC_SYNC_LOCK
0
R/W
Lock gain after sync word received and maximum number of
attempts. (As configured in AGCTST0.AGC_ATTEMPTS. Attempts
may be 0)
0
VGA_GAIN_OE
0
R/W
Use the VGA_GAIN value during RX instead of the AGC value.
FREND (0x05) – Front-end Control Register
Bit
Field Name
Reset
R/W
Description
15:4
-
0
W0
Reserved, write as 0.
3
-
1
W1
Reserved, write as 1.
2:0
PA_LEVEL[2:0]
7
R/W
PA output power level.
RSSI (0x06) - RSSI Status and Control Register
Bit
Field Name
Reset
R/W
Description
15:8
RSSI_VAL[7:0]
-
R
Averaged RSSI estimate on a logarithmic scale in signed two’s
complement format. Unit is 1 dB.
7:2
RSSI_CS_THRES[5:0]
0X3C
R/W
Offset= -54dB, see also page 44.
Carrier sense signal threshold value in signed two’s complement
format. Unit is 4 dB.
The CS_ABOVE_THRESHOLD_N signal goes low when the
received signal is above this value.
The CS_ABOVE_THRESHOLD_N signal is available on the
GIO1 pin or in the status word returned during SPI address byte.
The reset value corresponds to a threshold of approx. -69 dBm.
1:0
RSSI_FILT[1:0]
2
R/W
RSSI averaging filter length:
0: 0 bits (no filtering)
1: 1 bit
2: 4 bits
3: 8 bits
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CC2400
FREQEST (0x07) - Received frequency offset estimation
Field Name
Reset
R/W
Description
15:8
Bit
RX_FREQ_OFFSET[7:0]
-
R
Estimate of the received signals centre frequency comparison to
the ideal 1 MHz centre frequency. Two's complement signed
value. See page 42.
7:0
-
0
W0
Reserved, write as 0.
IOCFG (0x08) - I/O configuration register
Bit
Field Name
Reset
R/W
Description
15
-
0
W0
Reserved, write as 0.
14:9
GIO6_CFG[5:0]
11
R/W
Configuration of the GIO6 pin. See page 45 for options. The
reset value outputs the signal CRC_OK on pin GIO6.
8:3
GIO1_CFG[5:0]
60
R/W
How to use the GIO1 pin. See page 45 for options. The reset
value outputs the signal LOCK_STATUS on pin GIO1.
2:0
HSSD_SRC[2:0]
0
R/W
For test purposes only.
The HSSD (High Speed Serial Data) test module is used as
follows:
0: Off.
1: Output AGC status (gain setting / peak detector status /
accumulator value)
2: Output ADC I and Q values.
3: Output I/Q after digital down-mixing and channel filtering.
4: Output RX signal magnitude / frequency unfiltered (from
demodulator).
5: Output RX signal magnitude / frequency filtered (from
demodulator).
6: Output RSSI / RX frequency offset estimation
7: Input DAC values.
The HSSD test module requires that the FS is up and running as
it uses CLK_PRE (~150 MHZ) to produce its ~37.5 MHz data
clock and serialize its output words. Also, in order for HSSD to
function properly GRMDM.PIN_MODE must be set for HSSD.
FSMTC (0x0B) - Finite state machine time constants
Field Name
Reset
R/W
Description
15:13
Bit
TC_RXON2AGCEN[2:0]
3
R/W
The time in 5 s steps from RX is turned on until the AGC is
enabled. This time constant must be large enough to allow the
RX chain to settle so that the AGC algorithm starts working on a
proper signal. The default value corresponds to 15 us.
12:10
TC_PAON2SWITCH[2:0]
6
R/W
The time in s from TX is started until the TX/RX switch allows
the TX signal to pass.
9:6
RES[9:6]
10
R/W
Reserved
5:3
TC_TXEND2SWITCH[2:0]
2
R/W
The time in s from TX is stopped (for instance the last bit of the
packet is sent) until the RX/TX switch breaks the TX output and
the PKT signal is set.
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CC2400
Bit
2:0
Field Name
Reset
R/W
Description
TC_TXEND2PAOFF[2:0]
4
R/W
The time in s from TX is stopped until the TX chain is turned off
and the state machine goes to the next state. The PKT signal will
then go low. This value must be greater than
TC_TXEND2SWITCH[2:0].
RESERVED (0x0C) - Reserved register containing spare control and status bits
Bit
Field Name
Reset
R/W
Description
15:5
RES[15:5]
0
R/W
Reserved
RES[4:0]
0
R/W
Reserved
4:0
MANAND (0x0D) - Manual signal AND override register2
Bit
15
Field Name
Reset
R/W
Description
VGA_RESET_N
1
R/W
Overrides VGA_RESET_N used to reset the peak detectors in
the VGA in the RX chain.
Must be set to 0 during chip initialization.
14
LOCK_STATUS
1
R/W
Overrides the LOCK_STATUS top-level signal that indicates
whether VCO lock is achieved or not.
13
BALUN_CTRL
1
R/W
Overrides the BALUN_CTRL signal that controls whether the PA
should receive its required external biasing (1) or not (0) by
controlling the RX/TX output switch.
12
RXTX
1
R/W
Overrides the RXTX signal that controls whether the LO buffers
(0) or PA buffers (1) should be used.
11
PRE_PD
1
R/W
Power down of prescaler.
10
PA_N_PD
1
R/W
Power down of PA (negative path).
9
PA_P_PD
1
R/W
Power down of PA (positive path). When PA_N_PD=1 and
PA_P_PD=1 the up-conversion mixers are in powerdown.
8
DAC_LPF_PD
1
R/W
Power down of TX DACs.
7
BIAS_PD
1
R/W
Power down control of global bias generator + XOSC clock
buffer.
6
XOSC16M_PD
1
R/W
Power down control of 16 MHz XOSC core.
5
CHP_PD
1
R/W
Power down control of charge pump.
4
FS_PD
1
R/W
Power down control of VCO, I/Q generator, LO buffers.
2
For some important signals the value can be overridden manually by the MANAND and MANOVR registers. This is
done as follows for the hypothetical important signal IS:
IS_USED = (IS * IS_AND_MASK) + IS_OR_MASK,
using Boolean notation.
The AND-mask and OR-mask for the important signals listed resides in the MANAND and MANOR registers,
respectively.
Examples:
•
Writing 0xFFFE to MANAND and 0x0000 to MANOR will force LNAMIX_PD=0 whereas all other signals will be
unaffected.
•
Writing 0xFFFF to MANAND and 0x0001 to MANOVR will force LNAMIX_PD=1 whereas all other signals will be
unaffected.
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CC2400
Bit
Field Name
Reset
R/W
Description
3
ADC_PD
1
R/W
Power down control of the ADCs.
2
VGA_PD
1
R/W
Power down control of the VGA.
1
RXBPF_PD
1
R/W
Power down control of the band-pass receive filter.
0
LNAMIX_PD
1
R/W
Power down control of the LNA, down-conversion mixers and
front-end bias.
FSMSTATE (0x0E) - Finite state machine information and breakpoint
Bit
Field Name
Reset
R/W
Description
15:13
-
0
W0
Reserved, write as 0.
12:8
FSM_STATE_BKPT[4:0]
0
R/W
FSM breakpoint state. State=0 means that breakpoints are
disabled.
7:5
-
0
W0
Reserved, write as 0.
4:0
FSM_CUR_STATE[4:0]
-
R
Gives the current state of the finite state machine.
ADCTST (0x0F) - ADC Test Register
Field Name
Reset
R/W
Description
15
Bit
-
0
W0
Reserved, write as 0.
14:8
ADC_I[6:0]
-
R
Read the current ADC I-branch value.
7
-
0
W0
Reserved, write as 0.
6:0
ADC_Q[6:0]
-
R
Read the current ADC Q-branch value.
RXBPFTST (0x10) - Receiver Band-pass Filters Test Register
Bit
Field Name
Reset
R/W
Description
15
-
0
W0
Reserved, write as 0.
14
RXBPF_CAP_OE
0
R/W
RX band-pass filter capacitance calibration override enable.
13:7
RXBPF_CAP_O[6:0]
0
R/W
RX band-pass filter capacitance calibration override value.
6:0
RXBPF_CAP_RES[6:0]
-
R
RX band-pass filter capacitance calibration result.
0 Minimum capacitance in the feedback.
1: Second smallest capacitance setting.
…
127: Maximum capacitance in the feedback.
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Page 64 of 83
CC2400
PAMTST (0x11) - PA and Transmit Mixers Test Register
Field Name
Reset
R/W
Description
15:13
Bit
-
0
W0
Reserved, write as 0.
12
VC_IN_TEST_EN
0
R/W
When ATESTMOD_MODE=7 this controls whether the ATEST1 in
is used to output the VC node voltage (0) or to control the VC
node voltage (1).
11
ATESTMOD_PD
1
W
Power down of the analog test module.
10:8
ATESTMOD_MODE[2:0]
0
R/W
When ATESTMOD_PD=0, the function of the analog test module
is as follows:
0: Outputs “I” (ATEST2) and “Q” (ATEST1) from RxMIX.
1: Inputs “I” (ATEST2) and “Q” (ATEST1) to BPF.
2: Outputs “I” (ATEST2) and “Q” (ATEST1) from VGA.
3: Inputs “I” (ATEST2) and “Q” (ATEST1) to ADC.
4: Outputs “I” (ATEST2) and “Q” (ATEST1) from LPF.
5: Inputs “I” (ATEST2) and “Q” (ATEST1) to TxMIX.
6: Outputs “P” (ATEST2) and “N” (ATEST1) from Prescaler.
7: Connects TX IF to RX IF and simultaneously the ATEST1 pin to the
internal VC node (see VC_IN_TEST_EN).
7
-
0
W0
Reserved, write as 0.
6:5
TXMIX_CAP_ARRAY[1:0]
0
R/W
Selects varactor array settings in the transmit mixers.
4:3
TXMIX_CURRENT[1:0]
0
R/W
Transmit mixers current:
0: 1.72 mA
1: 1.88 mA
2: 2.05 mA
3 2.21 mA
2:0
PA_CURRENT[2:0]
3
R/W
Programming of the PA current
0: -3 current adjustment
1: -2 current adjustment
2: -1 current adjustment
3: Nominal setting
4: +1 current adjustment
5: +2 current adjustment
6: +3 current adjustment
7: +4 current adjustment
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Page 65 of 83
CC2400
LMTST (0x12) - LNA and receive mixers test register
Field Name
Reset
R/W
Description
15:14
Bit
-
0
W0
Reserved, write as 0.
13
RXMIX_HGM
1
R/W
Receiver mixers high gain mode enable.
12:11
RXMIX_TAIL[1:0]
1
R/W
Control of the receiver mixers output current.
0: 12 µA
1: 16 µA (Nominal)
2: 20 µA
3:24 µA
10:9
RXMIX_VCM[1:0]
1
R/W
Controls VCM level in the mixer feedback loop
0: 8 µA mixer current
1: 12 µA mixer current (Nominal)
2: 16 µA mixer current
3: 20 µA mixer current
Must be set to 0 during chip initialisation.
8:7
RXMIX_CURRENT[1:0]
2
R/W
Controls current in the mixer
0: 360 µA mixer current (x2)
1: 720 µA mixer current (x2)
2: 900 µA mixer current (x2) (Nominal)
3: 1260 µA mixer current (x2)
6:5
LNA_CAP_ARRAY[1:0]
1
R/W
Selects varactor array setting in the LNA
0: OFF
1: 0.1pF (x2) (Nominal)
2: 0.2pF (x2)
3: 0.3pF (x2)
4
LNA_LOWGAIN
0
R/W
Selects low gain mode of the LNA
0: 19 dB (Nominal)
1: 7 dB
3:2
LNA_GAIN[1:0]
0
R/W
Controls current in the LNA gain compensation branch
0: OFF (Nominal)
1: 100 µA LNA current
2: 300 µA LNA current
3: 1000 µA LNA current
1:0
LNA_CURRENT[1:0]
2
R/W
Controls main current in the LNA
0: 240 µA LNA current (x2)
1: 480 µA LNA current (x2)
2: 640 µA LNA current (x2) (Nominal)
3: 1280 µA LNA current (x2)
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Page 66 of 83
CC2400
MANOR (0x13) - Manual signal OR override register3
Bit
Field Name
Reset
R/W
Description
15
VGA_RESET_N
0
R/W
Overrides VGA_RESET_N used to reset the peak detectors in
the VGA in the RX chain.
14
LOCK_STATUS
0
R/W
Overrides the LOCK_STATUS top-level signal that indicates
whether VCO lock is achieved or not.
13
BALUN_CTRL
0
R/W
Overrides the BALUN_CTRL signal that controls whether the PA
should receive its required external biasing (1) or not (0) by
controlling the RX/TX output switch.
12
RXTX
0
R/W
Overrides the RXTX signal that controls whether the LO buffers
(0) or PA buffers (1) should be used.
11
PRE_PD
0
R/W
Power down of prescaler.
10
PA_N_PD
0
R/W
Power down of PA (negative path).
9
PA_P_PD
0
R/W
Power down of PA (positive path). When PA_N_PD=1 and
PA_P_PD=1 the up-conversion mixers are in power down.
8
DAC_LPF_PD
0
R/W
Power down of TX DACs.
7
BIAS_PD
0
R/W
Power down control of global bias generator + XOSC clock
buffer.
6
XOSC16M_PD
0
R/W
Power down control of 16 MHz XOSC core.
5
CHP_PD
0
R/W
Power down control of charge pump.
4
FS_PD
0
R/W
Power down control of VCO, I/Q generator, LO buffers.
3
ADC_PD
0
R/W
Power down control of the ADCs.
2
VGA_PD
0
R/W
Power down control of the VGA.
1
RXBPF_PD
0
R/W
Power down control of complex band-pass receive filter.
0
LNAMIX_PD
0
R/W
Power down control of LNA, down-conversion mixers and frontend bias.
MDMTST0 (0x14) - Modem Test Register 0
Bit
Field Name
Reset
R/W
Description
15:14
-
0
W0
Reserved, write as 0.
13
TX_PRNG
0
R/W
When set, the transmitted data is taken from a 10-bit PRNG
instead of from the DIO pin in un-buffered mode or from the
FIFO in buffered mode.
12
TX_1MHZ_OFFSET_N
0
R/W
Determines TX IF frequency:
0: 1 MHz (Not used)
1: 0 MHz (During initialization this bit must be set to a logical ’1’.)
11
INVERT_DATA
0
R/W
When this bit is set the data are inverted (internally) before
transmission, and inverted after reception.
10
AFC_ADJUST_ON_PACKET
0
R/W
When this bit is set to '1', modem parameters are adjusted for
slow tracking of the received signal as opposed to quick
acquisition when a packet is received in RX.
•
3
See footnote for MANAND register (address 0x0D) for description of the use of this register.
SWRS042A
Page 67 of 83
CC2400
Bit
9:8
Field Name
Reset
R/W
Description
AFC_SETTLING[1:0]
3
R/W
Controls how many max-min pairs that are used to compute the
output.
00: 1 pair
01: 2 pairs
10: 4 pairs
11: 8 pairs
7:0
AFC_DELTA[7:0]
75
R/W
Programmable level used in AFC-algorithm that indicates the
expected frequency deviation of the received signal. See page
42 for further details.
MDMTST1 (0x15) - Modem Test Register 1
Bit
Field Name
Reset
R/W
Description
15:7
-
0
W0
Reserved, write as 0.
6:0
BSYNC_THRESHOLD[6:0]
75
R/W
Threshold value used in clock recovery algorithm. Sets the level
for when re-synchronization takes place.
DACTST (0x16) - DAC Test Register
Field Name
Reset
R/W
Description
15
-
0
W0
Reserved, write as 0.
14:12
DAC_SRC[2:0]
0
R/W
The TX DACs data source is selected by DAC_SRC according
to:
Bit
0: Normal operation (from modulator).
1: The DAC_I_O and DAC_Q_O override values below.
2: From ADC
3: I/Q after digital down-mixing and channel filtering.
4: Full-spectrum White Noise (from PRNG.)
5: RX signal magnitude / frequency filtered (from demodulator).
6: RSSI / RX frequency offset estimation.
7: HSSD module.
This feature will often require the DACs to be manually turned on
in MANOVR and PAMTST.ATESTMOD_MODE=4.
11:6
DAC_I_O[5:0]
0
R/W
I-branch DAC override value.
5:0
DAC_Q_O[5:0]
0
R/W
Q-branch DAC override value.
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Page 68 of 83
CC2400
AGCTST0 (0x17) - AGC Test Register 0
Bit
Field Name
Reset
R/W
Description
AGC_SETTLE_BLANK_DN[2:
0]
4
R/W
AGC blanking enable/limit for negative gain changes.
12:11
AGC_WIN_SIZE[1:0]
2
R/W
AGC window size.
10:7
AGC_SETTLE_PEAK[3:0]
2
R/W
AGC peak detectors settling period.
6:3
AGC_SETTLE_ADC[3:0]
2
R/W
AGC ADC settling period.
2:0
AGC_ATTEMPTS[2:0]
0
R/W
The maximum number of attempts to set the gain.
15:13
0: Disabled
1-7: Duration of blanking signal in 8 MHz clock cycles.
AGCTST1 (0x18) - AGC Test Register 1
Bit
Field Name
Reset
R/W
Description
15
-
0
W0
Reserved, write as 0.
14
AGC_VAR_GAIN_SAT
1
R/W
Chooses the gain reduction upon saturation of the variable
gain stage:
0: -1/-3 gain steps
1: -3/-5 gain steps
13:11
AGC_SETTLE_BLANK_UP
[2:0]
0
R/W
AGC blanking enable/limit for positive gain changes.
0: Disabled
1-7: Duration of blanking signal in 8 MHz clock cycles.
10
PEAKDET_CUR_BOOST
0
R/W
Doubles the bias current in the peak-detectors in-between the
VGA stages when set.
9:6
AGC_MULT_SLOW[3:0]
0
R/W
AGC timing multiplier, slow mode.
5:2
AGC_SETTLE_FIXED[3:0]
4
R/W
AGC settling period, fixed gain step.
1:0
AGC_SETTLE_VAR[1:0]
0
R/W
AGC settling period, variable gain step.
AGCTST2 (0x19) - AGC Test Register 1
Bit
Field Name
Reset
R/W
Description
15:14
-
0
W0
Reserved, write as 0.
13:12
AGC_BACKEND_BLANKING
[1:0]
0
R/W
AGC blanking makes sure that the modem locks its bit
synchronization and centre frequency estimator when the AGC
changes the gain.
0: Disabled
1-3: Fixed/variable enable
11:9
AGC_ADJUST_M3DB[2:0]
0
R/W
AGC parameter -3 dB.
8:6
AGC_ADJUST_M1DB[2:0]
0
R/W
AGC parameter -1 dB.
5:3
AGC_ADJUST_P3DB[2:0]
0
R/W
AGC parameter +3 dB.
2:0
AGC_ADJUST_P1DB[2:0]
0
R/W
AGC parameter +1 dB.
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Page 69 of 83
CC2400
FSTST0 (0x1A) - Frequency Synthesiser Test Register 0
Bit
15:14
Field Name
Reset
R/W
Description
RXMIXBUF_CUR[1:0]
2
R/W
RX mixer buffer bias current.
0: 690uA
1: 980uA
2: 1.16mA (nominal)
3: 1.44mA
13:12
TXMIXBUF_CUR[1:0]
2
R/W
TX mixer buffer bias current.
0: 690uA
1: 980uA
2: 1.16mA (nominal)
3: 1.44mA
11
VCO_ARRAY_SETTLE_LONG
0
R/W
When '1' this control bit doubles the time allowed for VCO
settling during FS calibration.
10
VCO_ARRAY_OE
0
R/W
VCO array manual override enable.
9:5
VCO_ARRAY_O[4:0]
16
R/W
VCO array override value.
4:0
VCO_ARRAY_RES[4:0]
-
R
The resulting VCO array setting from the last calibration.
FSTST1 (0x1B) - Frequency Synthesiser Test Register 1
Bit
15
Field Name
Reset
R/W
Description
RXBPF_LOCUR
0
R/W
Controls reference bias current to RX band-pass filters:
0: 4 uA (nominal)
1: 3 uA
14
RXBPF_MIDCUR
0
R/W
Controls reference bias current to RX band-pass filters:
0: 4 uA (nominal)
1: 3.5 uA
13:10
VCO_CURRENT_REF[3:0]
4
R/W
The value of the reference current calibrated against during VCO
calibration.
9:4
VCO_CURRENT_K[5:0]
0
R/W
VCO current calibration constant (override value current B when
FSTST2.VCO_CURRENT_OE=1).
3
VC_DAC_EN
0
R/W
Controls the source of the VCO control voltage in normal
operation (PAMTST.VC_IN_TEST_EN=0):
0: Loop filter (closed loop PLL)
1: VC DAC (open loop PLL)
2:0
VC_DAC_VAL[2:0]
2
R/W
VC DAC output value. (The value of the reference voltage used
during VCO calibration.)
SWRS042A
Page 70 of 83
CC2400
FSTST2 (0x1C) - Frequency Synthesiser Test Register 2
Bit
Field Name
Reset
R/W
Description
15
-
0
W0
Reserved, write as 0.
14:13
VCO_CURCAL_SPEED[1:0]
0
R/W
VCO current calibration speed:
0: Normal
1: Undefined
2: Half speed
3: Undefined.
12
VCO_CURRENT_OE
0
R/W
VCO current manual override enable.
11:6
VCO_CURRENT_O[5:0]
24
R/W
VCO current override value (current A).
5:0
VCO_CURRENT_RES[5:0]
-
R
The resulting VCO current setting from last calibration.
FSTST3 (0x1D) - Frequency Synthesiser Test Register 3
Bit
Field Name
Reset
R/W
Description
15:14
-
0
W0
Reserved, write as 0.
13
CHP_TEST_UP
0
R/W
When CHP_DISABLE=1 forces the CHP to output "up" current.
12
CHP_TEST_DN
0
R/W
When CHP_DISABLE=1 forces the CHP to output "down"
current.
11
CHP_DISABLE
0
R/W
Set to disable charge pump during VCO calibration.
10
PD_DELAY
0
R/W
Selects short or long reset delay in phase detector:
0: Short reset delay
1: Long reset delay
9:8
CHP_STEP_PERIOD[1:0]
2
R/W
The charge pump current value step period:
0: 0.25 us
1: 0.5 us
2: 1 us
3: 4 us
7:4
STOP_CHP_CURRENT[3:0]
13
R/W
The charge pump current to stop at after the current is stepped
down from START_CHP_CURRENT after VCO calibration is
complete. The current is stepped down periodically with intervals
as defined in CHP_STEP_PERIOD.
3:0
START_CHP_CURRENT
[3:0]
13
R/W
The charge pump current to start with after VCO calibration is
complete. The current is then stepped down periodically to the
value STOP_CHP_CURRENT with intervals as defined in
CHP_STEP_PERIOD.
SWRS042A
Page 71 of 83
CC2400
MANFIDL (0x1E) - Manufacturer ID, Lower 16 Bit
Field Name
Reset
R/W
Description
15:12
Bit
PARTNUM[3:0]
1
R
The device part number. CC2400 has part number 0x001.
11:0
MANFID[11:0]
0X33D
R
Gives the JEDEC manufacturer ID. The actual manufacturer ID
can be found in MANIFID[7:1], the number of continuation
bytes in MANFID[11:8] and MANFID[0]=1.
Chipcon's JEDEC manufacturer ID is 0x7F 0x7F 0x7F 0x9E
(0x9E preceded by three continuation bytes.)
MANFIDH (0x1F) - Manufacturer ID, Upper 16 Bit
Field Name
Reset
R/W
Description
15:12
Bit
VERSION[3:0]
0
R
Chip version number.
11:0
PARTNUM[15:4]
0
R
The device part number. CC2400 has part number 0x001.
GRMDM (0x20) - Generic Radio Modem Control and Status
Bit
Field Name
Reset
R/W
Description
15
-
0
W0
Reserved, write as 0.
14:13
SYNC_ERRBITS_ALLOWED
[1:0]
0
R/W
Sync word detection occurs when the number of bits in the sync
word correlator different from that specified by the SYNC
registers is equal to or lower than SYNC_ERRBITS_ALLOWED.
12:11
PIN_MODE[1:0]
1
R/W
Selects between un-buffered mode, buffered mode or test mode.
The pin configuration is set according to Table 15.
0: Un-buffered mode
1: Buffered mode
2: HSSD test mode
3: Unused
10
PACKET_MODE
1
R/W
When this bit is set the packet mode is enabled. The pin
configuration is set according to Table 15.
In TX, this enables preamble generation, sync word, and CRC
appending (if enabled by CRC_ON) in the buffered mode.
In RX, this enables sync word detection in buffered and unbuffered modes, and CRC verification (if enabled by CRC_ON) in
buffered mode.
9:7
6:5
PRE_BYTES[2:0]
SYNC_WORD_SIZE[1:0]
3
3
R/W
R/W
The number of preamble bytes ("01010101") to be sent in packet
mode:
000: 0
001: 1
010: 2
011: 4
100: 8
101: 16
110: 32
111: Infinitely on
The size of the packet mode sync word sent in TX and correlated
against in RX:
00: The 8 MSB bits of SYNC_WORD.
01: The 16 MSB bits of SYNC_WORD.
10: The 24 MSB bits of SYNC_WORD.
11: The 32 MSB bits of SYNC_WORD.
4
CRC_ON
1
R/W
In packet mode a CRC is calculated and is transmitted after the
data in TX, and a CRC is calculated during reception in RX.
SWRS042A
Page 72 of 83
CC2400
Bit
3:2
Field Name
Reset
R/W
Description
DATA_FORMAT[1:0]
0
R/W
Selects line-coding format used during RX and TX operations.
00: NRZ
01: Manchester
10: 8/10 line-coding (Not applied to preambles or sync words)
11: Reserved
1
MODULATION_FORMAT
0
R/W
Modulation format of modem:
0: FSK/GFSK
1: Reserved
0
TX_GAUSSIAN_FILTER
1
R/W
When this bit is set the data sent in TX is Gaussian filtered
before transmission enabling GFSK
GRDEC (0x21) - Generic Radio Decimation Control and Status
Bit
Field Name
Reset
R/W
Description
15:13
-
0
W0
Reserved, write as 0.
12
IND_SATURATION
-
R
Signal indicates whether the accumulate-and-dump decimation
filters have saturated at some point since the last read. If
saturation occurs the DEC_SHIFT can be adjusted. The status
flag is cleared when reading the GRDEC register.
11:10
DEC_SHIFT[1:0]
0
R/W
Controls extra shifts in decimation, for extra precision.
Decimation shift value:
2: -2
3: -1
0: 0
1: 1
9:8
CHANNEL_DEC[1:0]
0
R/W
Selects channel filter bandwidth.
00: 1 MHz (used for 1Mbps and 250 kbps datarates)
01: 500 kHz (used for 10 kbps data rate)
01: 250 kHz
11: 125 kHz
7:0
DEC_VAL[7:0]
0
R/W
In combination with CHANNEL_DEC[1:0], DEC_VAL[7:0] is
used to program the data rate. See page 40 for a description.
PKTSTATUS (0x22) - Packet Mode Status
Bit
Field Name
Reset
R/W
Description
15:11
-
0
W0
Reserved, write as 0.
10
SYNC_WORD_RECEIVED
0
R
Indicates that the currently configured sync word has been
received since RX was turned on.
9
CRC_OK
-
R
Indicates that the two next bytes available to be read from the
FIFO equal the CRC16 calculated over the bytes already read
from the FIFO.
8
-
0
R
Reserved for future use.
7:0
-
-
R
Reserved for future use.
SWRS042A
Page 73 of 83
CC2400
INT (0x23) - Interrupt Register
Bit
Field Name
Reset
R/W
Description
15:8
-
0
W0
Reserved, write as 0.
7
-
0
R/W
Reserved.
6
PKT_POLARITY
0
R/W
Polarity of the PKT signal.
5
FIFO_POLARITY
0
R/W
Polarity of the FIFO signal. See Figure 10 for details.
4:0
FIFO_THRESHOLD[4:0]
30
R/W
The FIFO pin signals that the 32 bytes data FIFO is near empty
in TX or near full in RX. The threshold is used as follows:
# bytes in FIFO >= FIFO_THRESHOLD in RX
# bytes in FIFO <= 32 - FIFO_THRESHOLD in TX.
Reserved (0x24) – Reserved regiser
Field Name
Reset
R/W
Description
15:14
Bit
RES[15:14]
0
W0
Reserved for future use.
13:10
RES[13:10]
8
R/W
Reserved for future use.
9:7
RES[9:7]
0
R/W
Reserved for future use.
6:0
RES[6:0]
80
R/W
Reserved for future use.
Reserved (0x25) – Reserved register
Bit
Field Name
Reset
R/W
Description
15:12
RES[15:12]
0
W0
Reserved for future use.
11:0
RES[11:0]
0
R/W
Reserved for future use.
Reserved (0x26) – Reserved register
Bit
Field Name
Reset
R/W
Description
15:10
RES[15:10]
8
R/W
Reserved for future use.
9:0
RES[9:0]
0
R/W
Reserved for future use.
Reserved (0x27) – Reserved register
Bit
Field Name
Reset
R/W
Description
15:8
RES[15:8]
-
R
Reserved for future use.
7:3
RES[7:3]
0
R/W
Reserved for future use.
2:0
RES[2:0]
6
R/W
Reserved for future use.
Reserved (0x28) – Reserved register
Field Name
Reset
R/W
Description
15
Bit
RES[15]
0
R/W
Reserved for future use.
14:13
RES[14:13]
2
R/W
Reserved for future use.
12:7
RES[12:7]
63
R/W
Reserved for future use.
SWRS042A
Page 74 of 83
CC2400
Bit
6:0
Field Name
Reset
R/W
Description
RES[6:0]
0
R/W
Reserved for future use.
Reserved (0x29) – Reserved Register
Bit
Field Name
Reset
R/W
Description
15:8
RES[15:8]
0
W0
Reserved for future use.
7:3
RES[7:3]
0
R/W
Reserved for future use.
2:0
RES[2:0]
3
R/W
Reserved for future use.
Reserved (0x2A) – Reserved Register
Bit
Field Name
Reset
R/W
Description
15:11
RES[15:11]
0
W0
Reserved for future use.
10
RES[10]
0
R/W
Reserved for future use.
9:0
RES[9:0]
512
R/W
Reserved for future use.
Reserved (0x2B) – Reserved register
Bit
Field Name
Reset
R/W
Description
15:14
RES[15:14]
0
W0
Reserved for future use.
13
RES[13]
-
R/W
Reserved for future use.
12
RES[12]
-
R
Reserved for future use.
11:0
RES[11:0]
1953
R
Reserved for future use.
SYNCL (0x2C) - Sync Word, Lower 16 Bit
Bit
15:0
Field Name
Reset
R/W
Description
SYNCWORD[15:0]
0XDA26
R/W
Synchronisation word, lower 16 bit.
The default synchronization word of 0XD391DA26 has very
good DC, autocorrelation, and bit-run properties for all
synchronization word lengths.
SYNCH (0x2D) - Sync Word, Upper 16 Bit
Bit
15:0
Field Name
Reset
R/W
Description
SYNCWORD[31:16]
0XD391
R/W
Synchronisation word, upper 16 bit.
SWRS042A
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CC2400
50 Package Description (QFN48)
Note: The figure is an illustration only and not to scale.
Quad Flat Pack - No Lead Package (QFN)
b
D
E
D1
E1
e
QFN 48 Min
0.18
5.04
5.04
0.203
0.25
7.0
7.0
0.5
Max
1.0
0.30
5.24
5.24
The overall package height is 0.9 +/ 0.1 mm.
A
0.8
A1
L
0.43
0.53
0.63
L1
0.1
L2
0.30
0.40
0.50
All dimensions in mm
The package is compliant to JEDEC standard MO-220.
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CC2400
51 Recommended layout for package (QFN48)
Note: The figure is an illustration only and not to scale. There are nine 14 mil diameter via
holes distributed symmetrically in the ground pad under the package. See also the
CC2400EM reference design.
52 Package Thermal Properties
Thermal resistance
Air velocity [m/s]
0
Rth,j-a [K/W]
25.6
53 Soldering Information
Recommended soldering profile for both standard leaded packages and Pb-free packages is
according to IPC/JEDEC J-STD-020B, July 2002.
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CC2400
54 IC marking
Note: Please submit the entire marking information when contacting Chipcon technical
support about chip-related issues, not just the date code.
Example of QFN 48 standard leaded assembly
0440XAA
0440 is assembly year and week no.
XAA is lot code
SWRS042A
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CC2400
Example of QFN 48 RoHS compliant Pb-free assembly
A440XAA
A is to identify RoHS compliant Pb-free assembly
4 is to identify year 2004
40 is week no
XAA is lot code
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CC2400
55 Plastic Tube Specification
QFN 7x7 mm antistatic tube.
Package
QFN 48
Tube Width
8.5 ± 0.2 mm
Tube Specification
Tube Height
Tube Length
2.2 +0.2/-0.1
315 ± 1.25 mm
mm
Units per Tube
43
56 Carrier Tape and Reel Specification
Carrier tape and reel is in accordance with EIA Specification 481.
Package
Tape Width
QFN 48
16 mm
Tape and Reel Specification
Component
Hole
Reel
Pitch
Pitch
Diameter
12 mm
4 mm
13 inch
Units per Reel
4000
57 Ordering Information
Ordering part number
Description
MOQ
1170
CC2400-STB1
CC2400, QFN48 package, standard leaded assembly, tubes with
43 pcs per tube, 2.4 GHz RF transceiver.
43
1096
CC2400-STR1
CC2400, QFN48 package, standard leaded assembly, T&R with
4000 pcs per reel, 2.4 GHz RF transceiver.
4,000
1139
CC2400-RTB1
CC2400, QFN48 package, RoHS compliant Pb-free assembly,
tubes with 43 pcs per tube, 2.4 GHz RF transceiver.
43
1140
CC2400-RTR1
CC2400, QFN48 package, RoHS compliant Pb-free assembly,with
4000/T&R per reel, 2.4 GHz RF transceiver.
4,000
10031
CC2400DK
CC2400DK Development kit
1
10041
CC2400DBK
CC2400DBK, Demonstration Board Kit
1
1097
CC2400SK
CC2400 QFN48 package, standard leaded assembly, (5 pcs.)
1
1162
CC2400SK RoHS
CC2400 QFN48 package, RoHS compliant Pb-free assembly, 5
pcs.
1
MOQ = Minimum Order Quantity
T&R = tape and reel
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CC2400
58 General Information
58.1 Document History
Revision
Date
Description/Changes
1.5
1.4
2006-03-20
2006-01-16
1.3
2004-10-20
1.2
2004-02-05
1.1
2003-10-02
1.0
2003-09-10
Removed QLP information
Address information and ordering information have
been updated.
Various clarifications.
Added recommended PCB footprint.
Added package height.
Added radio control state diagram with state ID
numbers.
Added information about EN 300 328 and EN 300
440.
Added AFC, RSSI settling time and 20 dB bandwidth
to electrical specifications.
Electrical specifications updated.
Bit 5 of the STATUS register has been set as
reserved; see Errata Note 003 for details.
RSSI and carrier sense value calculation clarified and
corrected.
Added graphs showing typical current consumption,
sensitivity and output power as function of
temperature
Clarified packet handling and data buffering sections.
Description of the FSMTC register corrected.
Added example calculation to AFC description.
Updated ordering information with RoHS-compliant
Pb-free versions.
“CRC-16” replaced with “CRC”.
Reorganized electrical specification section.
Added chapter numbering.
Added QFN 48 package description.
Added IC marking description.
RSSI value calculation corrected.
Various clarifications.
Single-ended operation of the chip has been
removed.
Corrected value of DEC_VAL for 250 kbps data rate.
Added information that the core supply cannot be
switched off while I/O supply is still on.
Electrical specification updated.
Selectivity in-band is now measured using a FSK
modulated interferer.
Added note that choice of crystal package strongly
affects price.
Added section about low-latency systems.
Added graph of sensitivity vs. frequency offset.
Added plot of modulated spectrum.
Added more information about AFC.
Added information about using an external PA.
Operating conditions put into separate table.
Removed 32 kHz oscillator.
Added L71 to application circuit.
Modified component names in application circuit to
match reference design.
Corrected E2 and D2 package dimensions.
Minor corrections and editorial changes.
Added recommendation on length of preamble when
using GFSK.
Added Manchester data encoding.
Initial release.
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CC2400
58.2 Product Status Definitions
Data Sheet Identification
Product Status
Advance Information
Planned or Under
Development
Preliminary
Engineering Samples
and First Production
No Identification Noted
Full Production
Obsolete
Not In Production
Definition
This data sheet contains the design specifications for
product development. Specifications may change in
any manner without notice.
This data sheet contains preliminary data, and
supplementary data will be published at a later date.
Chipcon reserves the right to make changes at any
time without notice in order to improve design and
supply the best possible product.
This data sheet contains the final specifications.
Chipcon reserves the right to make changes at any
time without notice in order to improve design and
supply the best possible product.
This data sheet contains specifications on a product
that has been discontinued by Chipcon. The data
sheet is printed for reference information only.
58.3 Disclaimer
Chipcon AS believes the information contained herein is correct and accurate at the time of this printing. However,
Chipcon AS reserves the right to make changes to this product without notice. Chipcon AS does not assume any
responsibility for the use of the described product; neither does it convey any license under its patent rights, or the
rights of others. The latest updates are available at the Chipcon website or by contacting Chipcon directly.
As far as possible, major changes of product specifications and functionality, will be stated in product specific Errata
Notes published at the Chipcon website. Customers are encouraged to sign up to the Developers Newsletter for the
most recent updates on products and support tools.
When a product is discontinued this will be done according to Chipcon’s procedure for obsolete products as
described in Chipcon’s Quality Manual. This includes informing about last-time-buy options. The Quality Manual can
be downloaded from Chipcon’s website.
Compliance with regulations is dependent on complete system performance. It is the customer’s responsibility to
ensure that the system complies with regulations.
58.4 Trademarks
SmartRF is a registered trademark of Chipcon AS. SmartRF is Chipcon's RF technology platform with
RF library cells, modules and design expertise. Based on SmartRF technology Chipcon develops
standard component RF circuits as well as full custom ASICs based on customer requirements and this
technology.
All other trademarks, registered trademarks and product names are the sole property of their respective
owners.
58.5 Life Support Policy
This Chipcon product is not designed for use in life support appliances, devices, or other systems where
malfunction can reasonably be expected to result in significant personal injury to the user, or as a critical
component in any life support device or system whose failure to perform can be reasonably expected to
cause the failure of the life support device or system, or to affect its safety or effectiveness. Chipcon AS
customers using or selling these products for use in such applications do so at their own risk and agree to
fully indemnify Chipcon AS for any damages resulting from any improper use or sale.
© 2003, 2004, 2005, 2006 Chipcon AS. All rights reserved.
SWRS042A
Page 82 of 83
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TI warrants performance of its hardware products to the specifications applicable at the time of sale in
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