SX1231J - Semtech

SX1231J
WIRELESS & SENSING
DATASHEET
SX1231J Transceiver
Low Power Integrated UHF Transceiver
VR_DIG
RC
Oscillator
Mixers
RFIO
RSSI
AFC
GND
Division by
2, 4 or 6
PA_BOOST
PA1&2
Tank
Inductor
Loop
Filter
Frac-N PLL
Synthesizer
GENERAL DESCRIPTION
Smart metering and IEEE15.4d/g
Wireless sensor networks
Home and building automation
Wireless alarm and security systems
Industrial monitoring and control
DIO0
DIO1
DIO2
DIO3
DIO4
GND
Š
Š
Š
High Sensitivity: down to -120 dBm at 1.2 kbps
Š
Š
Š
Š
Š
Š
Š
Š
Š
Š
Š
Š
Š
Low current receive mode = 16 mA
Robust Selectivity: 42dB at 25kHz offset
Bullet-proof front end: IIP3 = -18 dBm, IIP2 = +35 dBm,
80 dB Blocking Immunity, no Image Frequency response
Low current sleep mode with register retention =100nA
Programmable TX Power: -18 to +17 dBm in 1dB steps
Constant RF performance over VDD voltage range
FSK bit rates up to 300 kb/s
Fully integrated synthesizer with a resolution of 61 Hz
FSK, GFSK, MSK, GMSK and OOK modulations
Built-in bit synchronizer for clock recovery
Incoming sync word recognition
115 dB+ dynamic range RSSI
Automatic RF sense with ultra-fast AFC
Packet engine with CRC, AES-128, and 66-byte FIFO
Built-in temperature sensor and low battery indicator
ORDERING INFORMATION
Active RFID tags
Remote keyless entry (RKE) and automotive
MARKETS
Š
Š
RXTX
KEY PRODUCT FEATURES
The SX1231J is an ARIB compliant highly integrated RF
transceiver which operates over all Japanese sub-GHz
frequency bands. Its highly integrated digital architecture
minimizes external components and provides flexibility for
optimizing the system parameters and performance. The
high sensitivity and exceptional blocking performance
combined with optimized IIP3 maximizes the range in
harshest environments. The industries lowest sleep current,
fastest wake times, and low receive current extend the
battery life for any application. The transmit output power is
programmable up to +17dBm and delivers constant
performance over the battery voltage lifetime. TrueRF™
technology enables a low-cost external component count
(eliminating SAW filter) while still satisfying ARIB, FCC, and
ETSI regulations. The device supports IEEE 15.4d/g
mandatory modes.
Š
Š
Š
Š
Š
Š
Š
RESET
SPI
DIO5
XO
32 MHz
XTAL
APPLICATIONS
Modulator
VR_PA
Ramp &
Control
Interpolation
& Filtering
PA0
Packet Engine & 66 Bytes FIFO
Single to
Differential
Σ/Δ
Modulators
Control Registers - Shift Registers - SPI Interface
LNA
Demodulator &
Bit Synchronizer
VR_ANA
Power Distribution System
Decimation and
& Filtering
VBAT1&2
Japan: ARIB STD-T67 from 426 to 470 MHz
Japan: ARIB STD-T108 from 915 to 930 MHz
Rev 2 - April 2012
Š
Page 1
Part Number
Package
Delivery
MOQ / Multiple
SX1231JIMLTRT
QFN24
Tape &
Reel
3000 pieces
Pb-free, Halogen free, RoHS/WEEE compliant product
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SX1231J
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Table of Contents
1.
2.
Page
General Description ................................................................................................................................................ 5
1.1.
Simplified Block Diagram ................................................................................................................................ 5
1.2.
Pin and Marking Diagram ................................................................................................................................ 6
1.3.
Pin Description ................................................................................................................................................ 7
Electrical Characteristics......................................................................................................................................... 8
2.1.
ESD Notice...................................................................................................................................................... 8
2.2.
Absolute Maximum Ratings ............................................................................................................................ 8
2.3.
Operating Range............................................................................................................................................. 8
2.4.
Chip Specification ........................................................................................................................................... 9
2.4.1. Power Consumption ................................................................................................................................... 9
2.4.2. Frequency Synthesis .................................................................................................................................. 9
2.4.3. Receiver ................................................................................................................................................... 10
2.4.4. Transmitter ............................................................................................................................................... 11
2.4.5. Digital Specification ...................................................................................................................................12
3.
Chip Description.................................................................................................................................................... 13
4.
Configuration and Status Registers ...................................................................................................................... 13
5.
4.1.
General Description ...................................................................................................................................... 13
4.2.
Common Configuration Registers ................................................................................................................. 16
4.3.
Transmitter Registers .................................................................................................................................... 19
4.4.
Receiver Registers ........................................................................................................................................ 20
4.5.
IRQ and Pin Mapping Registers.................................................................................................................... 22
4.6.
Packet Engine Registers............................................................................................................................... 24
4.7.
Temperature Sensor Registers ..................................................................................................................... 27
4.8.
Test Registers ............................................................................................................................................... 27
Application Information ......................................................................................................................................... 28
5.1.
Reference Design ......................................................................................................................................... 28
5.2.
Regulatory Compliance................................................................................................................................. 30
5.2.1. ARIB STD-T67 ......................................................................................................................................... 30
5.2.2. ARIB STD-T108 ....................................................................................................................................... 30
6.
Packaging Information .......................................................................................................................................... 31
6.1.
QFN 24 Encapsulation .................................................................................................................................. 31
6.2.
Thermal Impedance ...................................................................................................................................... 31
6.3.
Tape & Reel Specification............................................................................................................................. 32
7.
References............................................................................................................................................................ 33
8.
Revision History .................................................................................................................................................... 33
Rev 2 - April 2012
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SX1231J
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Index of Figures
Page
Figure 1. Block Diagram ................................................................................................................................................ 5
Figure 2. Pin Diagram (not to scale) .............................................................................................................................. 6
Figure 3. Marking Diagram ............................................................................................................................................ 6
Figure 4. SX1231J Evaluation Module Schematics ..................................................................................................... 28
Figure 5. QFN 24 Package Outline Drawing and Land Pattern ................................................................................... 31
Figure 6. Tape & Reel Specification, QFN Package .................................................................................................... 32
Index of Tables
Page
Table 1. SX1231J Pinouts .............................................................................................................................................. 7
Table 2. Absolute Maximum Ratings .............................................................................................................................. 8
Table 3. Operating Range .............................................................................................................................................. 8
Table 4. Power Consumption Specification .................................................................................................................... 9
Table 5. Frequency Synthesizer Specification ................................................................................................................ 9
Table 6. Receiver Specification .................................................................................................................................... 10
Table 7. Transmitter Specification ................................................................................................................................ 11
Table 8. Digital Specification ........................................................................................................................................ 12
Table 9. Registers Summary ........................................................................................................................................ 13
Table 10. Common Configuration Registers ................................................................................................................. 16
Table 11. Transmitter Registers ................................................................................................................................... 19
Table 12. Receiver Registers ....................................................................................................................................... 20
Table 13. IRQ and Pin Mapping Registers ................................................................................................................... 22
Table 14. Packet Engine Registers .............................................................................................................................. 24
Table 15. Temperature Sensor Registers ..................................................................................................................... 27
Table 16. Test Registers .............................................................................................................................................. 27
Table 17. SX1231J Evaluation Module BOM ............................................................................................................... 29
Table 18. Revision History ............................................................................................................................................ 33
Rev 2 - April 2012
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SX1231J
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Acronyms
BOM
BR
BW
CCITT
CRC
DAC
ETSI
FCC
Fdev
FIFO
FIR
FS
FSK
GUI
IC
ID
IF
IRQ
ITU
LFSR
LNA
LO
Rev 2 - April 2012
Bill Of Materials
Bit Rate
Bandwidth
Comité Consultatif International
Téléphonique et Télégraphique - ITU
Cyclic Redundancy Check
Digital to Analog Converter
European Telecommunications Standards
Institute
Federal Communications Commission
Frequency Deviation
First In First Out
Finite Impulse Response
Frequency Synthesizer
Frequency Shift Keying
Graphical User Interface
Integrated Circuit
IDentificator
Intermediate Frequency
Interrupt ReQuest
International Telecommunication Union
Linear Feedback Shift Register
Low Noise Amplifier
Local Oscillator
Page 4
LSB
MSB
NRZ
OOK
Least Significant Bit
Most Significant Bit
Non Return to Zero
On Off Keying
PA
PCB
PLL
Power Amplifier
Printed Circuit Board
Phase-Locked Loop
POR
RBW
RF
RSSI
Rx
SAW
SPI
SR
Stby
Tx
uC
VCO
XO
XOR
Power On Reset
Resolution BandWidth
Radio Frequency
Received Signal Strength Indicator
Receiver
Surface Acoustic Wave
Serial Peripheral Interface
Shift Register
Standby
Transmitter
Microcontroller
Voltage Controlled Oscillator
Crystal Oscillator
eXclusive OR
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SX1231J
WIRELESS & SENSING
DATASHEET
This product datasheet contains a detailed description of the SX1231J performance and functionality. Please consult the
Semtech website www.semtech.com for the latest updates or errata.
1. General Description
The SX1231J is a single-chip integrated circuit ideally suited for today's high performance ISM band RF applications. The
SX1231J's advanced features set, including state of the art packet engine greatly simplifies system design whilst the high
level of integration reduces the external BOM to a handful of passive decoupling and matching components. It is intended
for use as high-performance, low-cost FSK and OOK RF transceiver for robust frequency agile, half-duplex bi-directional
RF links, and where stable and constant RF performance is required over the full operating range of the device down to
1.8V.
Coupled with a link budget in excess of 135 dB, the advanced system features of the SX1231J include a 66 byte TX/RX
FIFO, configurable automatic packet handler, listen mode, temperature sensor and configurable DIOs which greatly
enhance system flexibility whilst at the same time significantly reducing MCU requirements.
The SX1231J complies with Japanese ARIB regulatory requirements and is available in a 5x 5 mm QFN 24 lead package.
1.1. Simplified Block Diagram
VR_DIG
RC
Oscillator
Power Distribution System
RFIO
Demodulator &
Bit Synchronizer
Σ/Δ
Modulators
Mixers
Single to
Differential
Decimation and
& Filtering
LNA
RSSI
AFC
GND
Division by
2, 4 or 6
Ramp &
Control
Loop
Filter
Frac-N PLL
Synthesizer
Modulator
VR_PA
Tank
Inductor
Interpolation
& Filtering
PA0
PA1&2
RESET
SPI
RXTX
DIO0
DIO1
DIO2
DIO3
DIO4
DIO5
XO
32 MHz
PA_BOOST
Control Registers - Shift Registers - SPI Interface
VR_ANA
Packet Engine & 66 Bytes FIFO
VBAT1&2
XTAL
GND
Frequency Synthesis
Transmitter Blocks
Primarily Analog
Receiver Blocks
Control Blocks
Primarily Digital
Figure 1. Block Diagram
Rev 2 - April 2012
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SX1231J
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1.2. Pin and Marking Diagram
The following diagram shows the pin arrangement of the SX1231J, top view.
Figure 2. Pin Diagram (not to scale)
Figure 3. Marking Diagram
Notes yyww refers to the date code
xxxxxx refers to the lot number
Rev 2 - April 2012
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1.3. Pin Description
Table 1
SX1231J Pinouts
Pin Number
Note
Name
Type
-
GROUND
-
Exposed ground pad
1
12
VBAT1
-
Supply voltage
2
13
VR_ANA
-
Regulated supply voltage for analogue circuitry
3
14
VR_DIG
-
Regulated supply voltage for digital blocks
4
15
XTA
I/O
XTAL connection
5
16
XTB
I/O
XTAL connection
6
17
RESET
I/O
Reset trigger input
-
18
GND
-
7
19
DIO0
I/O
Digital I/O, software configured
8
20
DIO1/DCLK
I/O
Digital I/O, software configured
9
21
DIO2/DATA
I/O
Digital I/O, software configured
10
22
DIO3
I/O
Digital I/O, software configured
11
23
DIO4
I/O
Digital I/O, software configured
12
24
DIO5
I/O
Digital I/O, software configured
-
25
GND
-
Ground
13
26
VBAT2
-
Supply voltage
14
27
GND
-
Ground
15
28
SCK
I
SPI Clock input
16
1
MISO
O
SPI Data output
17
2
MOSI
I
SPI Data input
18
3
NSS
I
SPI Chip select input
19
4
RXTX
O
Rx/Tx switch control: high in Tx
20
5
GND
-
Ground
21
6
RFIO
I/O
22
7
GND
-
Ground
23
8
PA_BOOST
O
Optional high-power PA output
-
9
GND
-
Ground
24
10
VR_PA
-
Regulated supply for the PA
-
11
GND
-
Ground
QFN
TSSOP
0
Description
Ground
RF input / output
PA_BOOST can be left floating if unused
Rev 2 - April 2012
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2. Electrical Characteristics
2.1. ESD Notice
The SX1231J is a high performance radio frequency device. It satisfies:
Š
Š
Š
Class 2 of the JEDEC standard JESD22-A114-B (Human Body Model) on all pins.
Class B of the JEDEC standard JESD22-A115-A (Machine Model) on all pins.
Class IV of the JEDEC standard JESD22-C101C (Charged Device Model) on pins VR_ANA, VR_DIG, RFIO,
PA_BOOST, VR_PA, Class III on all other pins.
It should thus be handled with all the necessary ESD precautions to avoid any permanent damage.
2.2. Absolute Maximum Ratings
Stresses above the values listed below may cause permanent device failure. Exposure to absolute maximum ratings for
extended periods may affect device reliability.
Table 2
Absolute Maximum Ratings
Symbol
Description
Min
Max
Unit
VDDmr
Supply Voltage
-0.5
3.9
V
Tmr
Temperature
-55
+115
°C
Tj
Junction temperature
-
+125
°C
Pmr
RF Input Level
-
+6
Min
Max
dBm
2.3. Operating Range
Table 3
Operating Range
Symbol
Description
Unit
VDDop
Supply voltage
1.8
3.6
V
Top
Operational temperature range
-40
+85
°C
Clop
Load capacitance on digital ports
-
25
pF
ML
RF Input Level
-
0
dBm
Rev 2 - April 2012
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2.4. Chip Specification
The tables below give the electrical specifications of the transceiver under the following conditions: Supply voltage VBAT1=
VBAT2=VDD=3.3 V, temperature = 25 °C, FXOSC = 32 MHz, FRF = 915 MHz, Pout = +13dBm, 2-level FSK modulation
without pre-filtering, FDA = 5 kHz, Bit Rate = 4.8 kb/s and terminated in a matched 50 Ohm impedance, unless otherwise
specified.
Note
Unless otherwise specified, the performances in the other frequency bands are similar or better.
2.4.1. Power Consumption
Table 4 Power Consumption Specification
Symbol
Description
IDDSL
Supply current in Sleep mode
IDDIDLE
Supply current in Idle mode
IDDST
Supply current in Standby mode
IDDFS
Conditions
Min
Typ
Max
-
0.1
1
uA
RC oscillator enabled
-
1.2
-
uA
Crystal oscillator enabled
-
1.25
1.5
mA
Supply current in Synthesizer
mode
-
9
-
mA
IDDR
Supply current in Receive mode
-
16
-
mA
IDDT
Supply current in Transmit mode
with appropriate matching, stable across VDD range
-
95
45
33
20
16
-
mA
mA
mA
mA
mA
RFOP = +17 dBm, on PA_BOOST
RFOP = +13 dBm, on RFIO pin
RFOP = +10 dBm, on RFIO pin
RFOP = 0 dBm, on RFIO pin
RFOP = -1 dBm, on RFIO pin
Unit
2.4.2. Frequency Synthesis
Table 5 Frequency Synthesizer Specification
Symbol
Description
Conditions
Min
Typ
Max
FR
Synthesizer Frequency Range
Programmable
424
862
-
510
1020
MHz
MHz
FXOSC
Crystal oscillator frequency
See section 5.1
-
32
-
MHz
TS_OSC
Crystal oscillator wake-up time
-
250
500
us
TS_FS
Frequency synthesizer wake-up
time to PllLock signal
-
80
150
us
TS_HOP
Frequency synthesizer hop time
at most 10 kHz away from the
target
-
20
20
50
50
80
80
80
-
us
us
us
us
us
us
us
FSTEP
Frequency synthesizer step
-
61.0
-
Hz
Rev 2 - April 2012
From Standby mode
200 kHz step
1 MHz step
5 MHz step
7 MHz step
12 MHz step
20 MHz step
25 MHz step
FSTEP = FXOSC/219
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FRC
RC Oscillator frequency
After calibration
-
62.5
-
kHz
BRF
Bit rate, FSK
Programmable
1.2
-
300
kbps
BRO
Bit rate, OOK
Programmable
1.2
-
32.768
kbps
FDA
Frequency deviation, FSK
Programmable
FDA + BRF/2 =< 500 kHz
0.6
-
300
kHz
2.4.3. Receiver
All receiver tests are performed with RxBw = 10 kHz (Single Side Bandwidth) as programmed in RegRxBw, receiving a
PN15 sequence with a BER of 0.1% (Bit Synchronizer is enabled), unless otherwise specified. The LNA impedance is set
to 200 Ohms, by setting bit LnaZin in RegLna to 1. Blocking tests are performed with an unmodulated interferer. The
wanted signal power for the Blocking Immunity, ACR, IIP2, IIP3 and AMR tests is set 3 dB above the nominal sensitivity
level.
Table 6
Receiver Specification
Symbol
Description
Conditions
Min
Typ
Max
RFS_F
FSK sensitivity, highest LNA gain
Unit
FDA = 5 kHz, BR = 1.2 kb/s
FDA = 5 kHz, BR = 4.8 kb/s
FDA = 40 kHz, BR = 38.4 kb/s
-
-118
-114
-105
-
dBm
dBm
dBm
FDA = 5 kHz, BR = 1.2 kb/s *
-
-120
-
dBm
BR = 4.8 kb/s
-
-112
-109
dBm
-13
-10
-
dB
RFS_O
OOK sensitivity, highest LNA gain
CCR
Co-Channel Rejection
ACR
Adjacent Channel Rejection
Offset = +/- 25 kHz
Offset = +/- 50 kHz
37
42
42
-
dB
dB
BI
Blocking Immunity
Offset = +/- 1 MHz
Offset = +/- 2 MHz
Offset = +/- 10 MHz
-
66
71
79
-
dB
dB
dB
Blocking Immunity
Wanted signal at sensitivity
+16dB
Offset = +/- 1 MHz
Offset = +/- 2 MHz
Offset = +/- 10 MHz
-
62
65
73
-
dB
dB
dB
AMR
AM Rejection, AM modulated
interferer with 100% modulation
depth, fm = 1 kHz, square
Offset = +/- 1 MHz
Offset = +/- 2 MHz
Offset = +/- 10 MHz
-
66
71
79
-
dB
dB
dB
IIP2
2nd order Input Intercept Point
Unwanted tones are 20 MHz
above the LO
Lowest LNA gain
Highest LNA gain
-
+75
+35
-
dBm
dBm
IIP3
3rd order Input Intercept point
Unwanted tones are 1MHz and
1.995 MHz above the LO
Lowest LNA gain
Highest LNA gain
-23
+20
-18
-
dBm
dBm
BW_SSB
Single Side channel filter BW
2.6
-
500
kHz
Rev 2 - April 2012
Programmable
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*
DATASHEET
IMR_OOK
Image rejection in OOK mode
Wanted signal level = -106 dBm
27
30
-
dB
TS_RE
Receiver wake-up time, from PLL
locked state to RxReady
RxBw = 10 kHz, BR = 4.8 kb/s
RxBw = 200 kHz, BR = 100 kb/s
-
1.7
96
-
ms
us
TS_RE_AGC
Receiver wake-up time, from PLL
locked state, AGC enabled
RxBw= 10 kHz, BR = 4.8 kb/s
RxBw = 200 kHz, BR = 100 kb/s
-
3.0
163
ms
us
TS_RE_AGC
&AFC
Receiver wake-up time, from PLL
lock state, AGC and AFC enabled
RxBw= 10 kHz, BR = 4.8 kb/s
RxBw = 200 kHz, BR = 100 kb/s
4.8
265
ms
us
TS_FEI
FEI sampling time
Receiver is ready
-
4.Tbit
-
-
TS_AFC
AFC Response Time
Receiver is ready
-
4.Tbit
-
-
TS_RSSI
RSSI Response Time
Receiver is ready
-
2.Tbit
-
-
DR_RSSI
RSSI Dynamic Range
AGC enabled
-
-115
0
-
dBm
dBm
Min
Max
Set SensitivityBoost in RegTestLna to 0x2D to reduce the noise floor in the receiver
2.4.4. Transmitter
Table 7 Transmitter Specification
Symbol
Description
Conditions
Min
Typ
Max
RF_OP
RF output power in 50 ohms
On RFIO pin
Programmable with 1dB steps
-
+13
-18
-
dBm
dBm
RF_OPH
Max RF output power, on
PA_BOOST pin
With external match to 50 ohms
-
+17
-
dBm
ΔRF_OP
RF output power stability
From VDD=1.8V to 3.6V
-
+/-0.3
-
dB
PHN
Transmitter Phase Noise
50 kHz Offset from carrier
868 / 915 MHz bands
434 / 315 MHz bands
-
-95
-99
-
dBc/
Hz
dBm
Max
Min
ACP
Transmitter adjacent channel
power (measured at 25 kHz offset)
BT=0.5 . Measurement conditions as
defined by EN 300 220-1 V2.1.1
-
-
-37
TS_TR
Transmitter wake up time, to the
first rising edge of DCLK
Frequency Synthesizer enabled,
PaRamp = 10 us, BR = 4.8 kb/s.
-
120
-
Rev 2 - April 2012
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2.4.5. Digital Specification
Conditions: Temp = 25°C, VDD = 3.3V, FXOSC = 32 MHz, unless otherwise specified.
Table 8
Digital Specification
Symbol
Description
VIH
Min
Typ
Max
Digital input level high
0.8
-
-
VDD
VIL
Digital input level low
-
-
0.2
VDD
VOH
Digital output level high
Imax = 1 mA
0.9
-
-
VDD
VOL
Digital output level low
Imax = -1 mA
-
-
0.1
VDD
FSCK
SCK frequency
-
-
10
MHz
tch
SCK high time
50
-
-
ns
tcl
SCK low time
50
-
-
ns
trise
SCK rise time
-
5
-
ns
tfall
SCK fall time
-
5
-
ns
tsetup
MOSI setup time
from MOSI change to SCK rising
edge
30
-
-
ns
thold
MOSI hold time
from SCK rising edge to MOSI
change
60
-
-
ns
tnsetup
NSS setup time
from NSS falling edge to SCK rising
edge
30
-
-
ns
tnhold
NSS hold time
from SCK falling edge to NSS rising
edge, normal mode
30
-
-
ns
tnhigh
NSS high time between SPI
accesses
20
-
-
ns
T_DATA
DATA hold and setup time
250
-
-
ns
Rev 2 - April 2012
Conditions
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3. Chip Description
Semtech’s transceivers SX1231 and SX1231J share the architecture and functionnalities. For a complete description of the
feature set, please refer to [1]
4. Configuration and Status Registers
4.1. General Description
Table 9
Registers Summary
Reset
(built-in)
Default
(recom
mended)
Address
Register Name
0x00
RegFifo
0x00
FIFO read/write access
0x01
RegOpMode
0x04
Operating modes of the transceiver
0x02
RegDataModul
0x00
Data operation mode and Modulation settings
0x03
RegBitrateMsb
0x1A
Bit Rate setting, Most Significant Bits
0x04
RegBitrateLsb
0x0B
Bit Rate setting, Least Significant Bits
0x05
RegFdevMsb
0x00
Frequency Deviation setting, Most Significant Bits
0x06
RegFdevLsb
0x52
Frequency Deviation setting, Least Significant Bits
0x07
RegFrfMsb
0xE4
RF Carrier Frequency, Most Significant Bits
0x08
RegFrfMid
0xC0
RF Carrier Frequency, Intermediate Bits
0x09
RegFrfLsb
0x00
RF Carrier Frequency, Least Significant Bits
0x0A
RegOsc1
0x41
RC Oscillators Settings
0x0B
RegAfcCtrl
0x00
AFC control in low modulation index situations
0x0C
RegLowBat
0x02
Low Battery Indicator Settings
0x0D
RegListen1
0x92
Listen Mode settings
0x0E
RegListen2
0xF5
Listen Mode Idle duration
0x0F
RegListen3
0x20
Listen Mode Rx duration
0x10
RegVersion
0x23
Semtech ID relating the silicon revision
0x11
RegPaLevel
0x9F
PA selection and Output Power control
0x12
RegPaRamp
0x09
Control of the PA ramp time in FSK mode
0x13
RegOcp
0x1A
Over Current Protection control
0x14
Reserved14
0x40
-
0x15
Reserved15
0xB0
-
Rev 2 - April 2012
Description
Page 13
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SX1231J
WIRELESS & SENSING
DATASHEET
Reset
(built-in)
Default
(recom
mended)
Address
Register Name
0x16
Reserved16
0x7B
-
0x17
Reserved17
0x9B
-
0x18
RegLna
0x08
0x88
LNA settings
0x19
RegRxBw
0x86
0x55
Channel Filter BW Control
0x1A
RegAfcBw
0x8A
0x8B
Channel Filter BW control during the AFC routine
0x1B
RegOokPeak
0x40
OOK demodulator selection and control in peak mode
0x1C
RegOokAvg
0x80
Average threshold control of the OOK demodulator
0x1D
RegOokFix
0x06
Fixed threshold control of the OOK demodulator
0x1E
RegAfcFei
0x10
AFC and FEI control and status
0x1F
RegAfcMsb
0x00
MSB of the frequency correction of the AFC
0x20
RegAfcLsb
0x00
LSB of the frequency correction of the AFC
0x21
RegFeiMsb
0x00
MSB of the calculated frequency error
0x22
RegFeiLsb
0x00
LSB of the calculated frequency error
0x23
RegRssiConfig
0x02
RSSI-related settings
0x24
RegRssiValue
0xFF
RSSI value in dBm
0x25
RegDioMapping1
0x00
Mapping of pins DIO0 to DIO3
0x26
RegDioMapping2
0x27
RegIrqFlags1
0x80
Status register: PLL Lock state, Timeout, RSSI > Threshold...
0x28
RegIrqFlags2
0x00
Status register: FIFO handling flags, Low Battery detection...
0x29
RegRssiThresh
0x2A
RegRxTimeout1
0x00
Timeout duration between Rx request and RSSI detection
0x2B
RegRxTimeout2
0x00
Timeout duration between RSSI detection and PayloadReady
0x2C
RegPreambleMsb
0x00
Preamble length, MSB
0x2D
RegPreambleLsb
0x03
Preamble length, LSB
0x2E
RegSyncConfig
0x98
Sync Word Recognition control
0x2F-0x36
RegSyncValue1-8
0x37
RegPacketConfig1
0x10
Packet mode settings
0x38
RegPayloadLength
0x40
Payload length setting
0x39
RegNodeAdrs
0x00
Node address
Rev 2 - April 2012
0x05
0x07
0xFF
0xE4
0x00
0x01
Description
Mapping of pins DIO4 and DIO5, ClkOut frequency
RSSI Threshold control
Sync Word bytes, 1 through 8
Page 14
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SX1231J
WIRELESS & SENSING
DATASHEET
Default
(recom
mended)
Reset
(built-in)
Address
Register Name
0x3A
RegBroadcastAdrs
0x00
Broadcast address
0x3B
RegAutoModes
0x00
Auto modes settings
0x3C
RegFifoThresh
0x3D
RegPacketConfig2
0x02
Packet mode settings
0x3E-0x4D
RegAesKey1-16
0x00
16 bytes of the cypher key
0x4E
RegTemp1
0x01
Temperature Sensor control
0x4F
RegTemp2
0x00
Temperature readout
0x58
RegTestLna
0x1B
Sensitivity boost
0x59
RegTestTcxo
0x09
TCXO or XTAL input setting
0x6F
RegTestDagc
0x71
RegTestAfc
0x00
0x50 +
RegTest
-
Note
0x0F
0x8F
0x00
0x30
Description
Fifo threshold, Tx start condition
Fading Margin Improvement
AFC offset for low modulation index AFC
Internal test registers
- Reset values are automatically refreshed in the chip at Power On Reset
- Default values are the Semtech recommended register values, optimizing the device operation
- Registers for which the Default value differs from the Reset value are denoted by a * in the tables of section 4
Rev 2 - April 2012
Page 15
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SX1231J
WIRELESS & SENSING
DATASHEET
4.2. Common Configuration Registers
Table 10 Common Configuration Registers
Name
(Address)
RegFifo
(0x00)
RegOpMode
(0x01)
RegDataModul
(0x02)
RegBitrateMsb
(0x03)
Rev 2 - April 2012
Bits Variable Name
7-0
Mode
Default
Description
Value
0x00 FIFO data input/output
Fifo
rw
7
SequencerOff
rw
0
6
ListenOn
rw
0
5
ListenAbort
w
0
4-2
Mode
rw
001
1-0
7
6-5
DataMode
r
r
rw
00
0
00
4-3
ModulationType
rw
00
2
1-0
ModulationShaping
r
rw
0
00
7-0
BitRate(15:8)
rw
0x1a
Page 16
Controls the automatic Sequencer (see section 4.2 ):
0 Æ Operating mode as selected with Mode bits in
RegOpMode is automatically reached with the Sequencer
1 Æ Mode is forced by the user
Enables Listen mode, should be enabled whilst in
Standby mode:
0 Æ Off (see section 4.3)
1 Æ On
Aborts Listen mode when set together with ListenOn=0
See section 4.3.4 for details
Always reads 0.
Transceiver’s operating modes:
000 Æ Sleep mode (SLEEP)
001 Æ Standby mode (STDBY)
010 Æ Frequency Synthesizer mode (FS)
011 Æ Transmitter mode (TX)
100 Æ Receiver mode (RX)
others Æ reserved
Reads the value corresponding to the current chip mode
unused
unused
Data processing mode:
00 Æ Packet mode
01 Æ reserved
10 Æ Continuous mode with bit synchronizer
11 Æ Continuous mode without bit synchronizer
Modulation scheme:
00 Æ FSK
01 Æ OOK
10 - 11 Æ reserved
unused
Data shaping:
in FSK:
00 Æ no shaping
01 Æ Gaussian filter, BT = 1.0
10 Æ Gaussian filter, BT = 0.5
11 Æ Gaussian filter, BT = 0.3
in OOK:
00 Æ no shaping
01 Æ filtering with fcutoff = BR
10 Æ filtering with fcutoff = 2*BR
11 Æ reserved
MSB of Bit Rate (Chip Rate when Manchester encoding is
enabled)
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RegBitrateLsb
(0x04)
7-0
BitRate(7:0)
rw
RegFdevMsb
(0x05)
7-6
5-0
7-0
Fdev(13:8)
Fdev(7:0)
r
rw
rw
RegFdevLsb
(0x06)
0x0b
LSB of Bit Rate (Chip Rate if Manchester encoding is
enabled)
FXOSC
BitRate = ----------------------------------BitRate (15,0)
Default value: 4.8 kb/s
00
unused
000000 MSB of the frequency deviation
0x52 LSB of the frequency deviation
Fdev = Fstep × Fdev (15,0)
RegFrfMsb
(0x07)
7-0
Frf(23:16)
rw
0xe4
Default value: 5 kHz
MSB of the RF carrier frequency
RegFrfMid
(0x08)
7-0
Frf(15:8)
rw
0xc0
Middle byte of the RF carrier frequency
RegFrfLsb
(0x09)
7-0
Frf(7:0)
rw
0x00
LSB of the RF carrier frequency
RegOsc1
(0x0A)
7
RcCalStart
w
6
RcCalDone
r
Frf = Fstep × Frf ( 23 ;0 )
RegAfcCtrl
(0x0B)
5-0
7-6
5
AfcLowBetaOn
r
r
rw
RegLowBat
(0x0C)
4-0
7-5
4
LowBatMonitor
r
r
rw
LowBatOn
rw
LowBatTrim
rw
3
2-0
Rev 2 - April 2012
Default value: Frf = 915 MHz (32 MHz XO)
Triggers the calibration of the RC oscillator when set.
Always reads 0. RC calibration must be triggered in
Standby mode.
1
0 Æ RC calibration in progress
1 Æ RC calibration is over
000001 unused
00
unused
0
Improved AFC routine for signals with modulation index
lower than 2. Refer to section 3.5.16 for details
0 Æ Standard AFC routine
1 Æ Improved AFC routine
00000 unused
000
unused
Real-time (not latched) output of the Low Battery detector,
when enabled.
0
Low Battery detector enable signal
0 Æ LowBat off
1 Æ LowBat on
010
Trimming of the LowBat threshold:
000 Æ 1.695 V
001 Æ 1.764 V
010 Æ 1.835 V
011 Æ 1.905 V
100 Æ 1.976 V
101 Æ 2.045 V
110 Æ 2.116 V
111 Æ 2.185 V
0
Page 17
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SX1231J
WIRELESS & SENSING
RegListen1
(0x0D)
RegListen2
(0x0E)
RegListen3
(0x0F)
DATASHEET
7-6
ListenResolIdle
rw
10
5-4
ListenResolRx
rw
01
3
ListenCriteria
rw
0
2-1
ListenEnd
rw
01
0
7-0
ListenCoefIdle
r
rw
0
0xf5
Resolution of Listen mode Idle time (calibrated RC osc):
00 Æ reserved
01 Æ 64 us
10 Æ 4.1 ms
11 Æ 262 ms
Resolution of Listen mode Rx time (calibrated RC osc):
00 Æ reserved
01 Æ 64 us
10 Æ 4.1 ms
11 Æ 262 ms
Criteria for packet acceptance in Listen mode:
0 Æ signal strength is above RssiThreshold
1 Æ signal strength is above RssiThreshold and
SyncAddress matched
Action taken after acceptance of a packet in Listen mode:
00 Æ chip stays in Rx mode. Listen mode stops and must
be disabled (see section 4.3).
01 Æ chip stays in Rx mode until PayloadReady or
Timeout interrupt occurs. It then goes to the mode defined
by Mode. Listen mode stops and must be disabled (see
section 4.3).
10 Æ chip stays in Rx mode until PayloadReady or
Timeout interrupt occurs. Listen mode then resumes in
Idle state. FIFO content is lost at next Rx wakeup.
11 Æ Reserved
unused
Duration of the Idle phase in Listen mode.
t ListenIdle = ListenCoefIdle ⋅ ListenResolIdle
7-0
ListenCoefRx
rw
0x20
Duration of the Rx phase in Listen mode (startup time
included, see section 4.2.3)
t ListenRx = ListenCoefRx ⋅ ListenResolRx
RegVersion
(0x10)
Rev 2 - April 2012
7-0
Version
r
0x23
Page 18
Version code of the chip. Bits 7-4 give the full revision
number; bits 3-0 give the metal mask revision number.
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WIRELESS & SENSING
DATASHEET
4.3. Transmitter Registers
Table 11 Transmitter Registers
Name
(Address)
RegPaLevel
(0x11)
7
6
5
4-0
Pa0On *
Pa1On *
Pa2On *
OutputPower
rw
rw
rw
rw
Default
Value
1
0
0
11111
RegPaRamp
(0x12)
7-4
3-0
PaRamp
r
rw
0000
1001
RegOcp
(0x13)
7-5
4
OcpOn
r
rw
000
1
3-0
OcpTrim
rw
1010
Bits Variable Name
Mode
Description
Enables PA0, connected to RFIO and LNA
Enables PA1, on PA_BOOST pin
Enables PA2, on PA_BOOST pin
Output power setting, with 1 dB steps
Pout = -18 + OutputPower [dBm] , with PA0 or PA1
Pout = -14 + OutputPower [dBm] , with PA1 and PA2
(limited to the 16 upper values of OutputPower)
unused
Rise/Fall time of ramp up/down in FSK
0000 Æ 3.4 ms
0001 Æ 2 ms
0010 Æ 1 ms
0011 Æ 500 us
0100 Æ 250 us
0101 Æ 125 us
0110 Æ 100 us
0111 Æ 62 us
1000 Æ 50 us
1001 Æ 40 us
1010 Æ 31 us
1011 Æ 25 us
1100 Æ 20 us
1101 Æ 15 us
1110 Æ 12 us
1111 Æ 10 us
unused
Enables overload current protection (OCP) for the PA:
0 Æ OCP disabled
1 Æ OCP enabled
Trimming of OCP current:
Imax = 45 + 5 × OcpTrim ( mA )
95 mA OCP by default
Note
*Power Amplifier truth table is available in Table 10.
Rev 2 - April 2012
Page 19
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SX1231J
WIRELESS & SENSING
DATASHEET
4.4. Receiver Registers
Table 12 Receiver Registers
Name
(Address)
Bits Variable Name
Mode
Default
Description
Value
0x40 unused
Reserved14
(0x14)
7-0
-
r
Reserved15
(0x15)
7-0
-
r
0xB0
unused
Reserved16
(0x16)
7-0
-
r
0x7B
unused
Reserved17
(0x17)
7-0
-
r
0x9B
unused
LnaZin
rw
1
*
6
5-3
2-0
LnaCurrentGain
LnaGainSelect
r
r
rw
0
001
000
7-5
DccFreq
rw
010
*
RegLna
(0x18)
RegRxBw
(0x19)
7
4-3
RxBwMant
rw
10
*
2-0
RxBwExp
rw
101
*
LNA’s input impedance
0 Æ 50 ohms
1 Æ 200 ohms
unused
Current LNA gain, set either manually, or by the AGC
LNA gain setting:
000 Æ gain set by the internal AGC loop
001 Æ G1 = highest gain
010 Æ G2 = highest gain – 6 dB
011 Æ G3 = highest gain – 12 dB
100 Æ G4 = highest gain – 24 dB
101 Æ G5 = highest gain – 36 dB
110 Æ G6 = highest gain – 48 dB
111 Æ reserved
Cut-off frequency of the DC offset canceller (DCC):
4 × RxBw fc = ----------------------------------------DccFreq + 2
2π × 2
~4% of the RxBw by default
Channel filter bandwidth control:
00 Æ RxBwMant = 16
10 Æ RxBwMant = 24
01 Æ RxBwMant = 20
11 Æ reserved
Channel filter bandwidth control:
FSK Mode:
FXOSC
RxBw = ----------------------------------------------------------------RxBwExp + 2
RxBwMant × 2
OOK Mode:
FXOSC
RxBw = ----------------------------------------------------------------RxBwExp + 3
RxBwMant × 2
RegAfcBw
(0x1A)
Rev 2 - April 2012
7-5
4-3
2-0
DccFreqAfc
RxBwMantAfc
RxBwExpAfc
rw
rw
rw
100
01
011 *
Page 20
See Table 13 for tabulated values
DccFreq parameter used during the AFC
RxBwMant parameter used during the AFC
RxBwExp parameter used during the AFC
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SX1231J
WIRELESS & SENSING
RegOokPeak
(0x1B)
RegOokAvg
(0x1C)
DATASHEET
7-6
OokThreshType
rw
01
5-3
OokPeakTheshStep
rw
000
2-0
OokPeakThreshDec
rw
000
7-6
OokAverageThreshFilt
rw
10
Selects type of threshold in the OOK data slicer:
00 Æ fixed
10 Æ average
01 Æ peak
11 Æ reserved
Size of each decrement of the RSSI threshold in the OOK
demodulator:
000 Æ 0.5 dB
001 Æ 1.0 dB
010 Æ 1.5 dB
011 Æ 2.0 dB
100 Æ 3.0 dB
101 Æ 4.0 dB
110 Æ 5.0 dB
111 Æ 6.0 dB
Period of decrement of the RSSI threshold in the OOK
demodulator:
000 Æ once per chip
001 Æ once every 2 chips
010 Æ once every 4 chips
011 Æ once every 8 chips
100 Æ twice in each chip
101 Æ 4 times in each chip
110 Æ 8 times in each chip 111 Æ 16 times in each chip
Filter coefficients in average mode of the OOK
demodulator:
00 Æ fC ≈ chip rate / 32.π
01 Æ fC ≈ chip rate / 8.π
10 Æ fC ≈ chip rate / 4.π
RegOokFix
(0x1D)
5-0
7-0
OokFixedThresh
r
rw
11 ÆfC ≈ chip rate / 2.π
000000 unused
0110 Fixed threshold value (in dB) in the OOK demodulator.
(6dB) Used when OokThresType = 00
7
6
FeiDone
r
r
0
0
5
4
FeiStart
AfcDone
w
r
0
1
3
AfcAutoclearOn
rw
0
2
AfcAutoOn
rw
0
1
0
7-0
AfcClear
AfcStart
AfcValue(15:8)
w
w
r
0
0
0x00
RegAfcLsb
(0x20)
7-0
AfcValue(7:0)
r
0x00
RegFeiMsb
(0x21)
7-0
FeiValue(15:8)
r
-
MSB of the measured frequency offset, 2’s complement
RegFeiLsb
(0x22)
7-0
FeiValue(7:0)
r
-
LSB of the measured frequency offset, 2’s complement
Frequency error = FeiValue x Fstep
RegRssiConfig
(0x23)
7-2
1
RssiDone
r
r
0
7-0
RssiStart
RssiValue
w
r
RegAfcFei
(0x1E)
RegAfcMsb
(0x1F)
RegRssiValue
(0x24)
Rev 2 - April 2012
unused
0 Æ FEI is on-going
1 Æ FEI finished
Triggers a FEI measurement when set. Always reads 0.
0 Æ AFC is on-going
1 Æ AFC has finished
Only valid if AfcAutoOn is set
0 Æ AFC register is not cleared before a new AFC phase
1 Æ AFC register is cleared before a new AFC phase
0 Æ AFC is performed each time AfcStart is set
1 Æ AFC is performed each time Rx mode is entered
Clears the AfcValue if set in Rx mode. Always reads 0
Triggers an AFC when set. Always reads 0.
MSB of the AfcValue, 2’s complement format
LSB of the AfcValue, 2’s complement format
Frequency correction = AfcValue x Fstep
000000 unused
1
0 Æ RSSI is on-going
1 Æ RSSI sampling is finished, result available
0
Trigger a RSSI measurement when set. Always reads 0.
0xFF Absolute value of the RSSI in dBm, 0.5dB steps.
RSSI = -RssiValue/2 [dBm]
Page 21
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SX1231J
WIRELESS & SENSING
DATASHEET
4.5. IRQ and Pin Mapping Registers
Table 13 IRQ and Pin Mapping Registers
Name
(Address)
RegDioMapping1
(0x25)
RegDioMapping2
(0x26)
RegIrqFlags1
(0x27)
Rev 2 - April 2012
Bits Variable Name
Mode
Default
Value
00
00
00
00
00
00
0
111
*
7-6
5-4
3-2
1-0
7-6
5-4
3
2-0
Dio0Mapping
Dio1Mapping
Dio2Mapping
Dio3Mapping
Dio4Mapping
Dio5Mapping
ClkOut
rw
rw
rw
rw
rw
rw
r
rw
7
ModeReady
r
1
6
RxReady
r
0
5
TxReady
r
0
4
PllLock
r
0
3
Rssi
rwc
0
2
Timeout
r
0
1
AutoMode
r
0
0
SyncAddressMatch
r/rwc
0
Page 22
Description
Mapping of pins DIO0 to DIO5
See Table 20 for mapping in Continuous mode
See Table 21 for mapping in Packet mode
unused
Selects CLKOUT frequency:
000 Æ FXOSC
001 Æ FXOSC / 2
010 Æ FXOSC / 4
011 Æ FXOSC / 8
100 Æ FXOSC / 16
101 Æ FXOSC / 32
110 Æ RC (automatically enabled)
111 Æ OFF
Set when the operation mode requested in Mode, is ready
- Sleep: Entering Sleep mode
- Standby: XO is running
- FS: PLL is locked
- Rx: RSSI sampling starts
- Tx: PA ramp-up completed
Cleared when changing operating mode.
Set in Rx mode, after RSSI, AGC and AFC.
Cleared when leaving Rx.
Set in Tx mode, after PA ramp-up.
Cleared when leaving Tx.
Set (in FS, Rx or Tx) when the PLL is locked.
Cleared when it is not.
Set in Rx when the RssiValue exceeds RssiThreshold.
Cleared when leaving Rx.
Set when a timeout occurs (see TimeoutRxStart and
TimeoutRssiThresh)
Cleared when leaving Rx or FIFO is emptied.
Set when entering Intermediate mode.
Cleared when exiting Intermediate mode.
Please note that in Sleep mode a small delay can be
observed between AutoMode interrupt and the
corresponding enter/exit condition.
Set when Sync and Address (if enabled) are detected.
Cleared when leaving Rx or FIFO is emptied.
This bit is read only in Packet mode, rwc in Continuous
mode
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SX1231J
WIRELESS & SENSING
RegIrqFlags2
(0x28)
DATASHEET
7
FifoFull
r
0
6
5
FifoNotEmpty
FifoLevel
r
r
0
0
4
FifoOverrun
rwc
0
3
PacketSent
r
0
2
PayloadReady
r
0
1
CrcOk
r
0
0
LowBat
rwc
-
RegRssiThresh
(0x29)
7-0
RssiThreshold
rw
0xE4
*
RegRxTimeout1
(0x2A)
7-0
TimeoutRxStart
rw
0x00
RegRxTimeout2
(0x2B)
7-0
TimeoutRssiThresh
rw
0x00
Rev 2 - April 2012
Page 23
Set when FIFO is full (i.e. contains 66 bytes), else
cleared.
Set when FIFO contains at least one byte, else cleared
Set when the number of bytes in the FIFO strictly exceeds
FifoThreshold, else cleared.
Set when FIFO overrun occurs. (except in Sleep mode)
Flag(s) and FIFO are cleared when this bit is set. The
FIFO then becomes immediately available for the next
transmission / reception.
Set in Tx when the complete packet has been sent.
Cleared when exiting Tx.
Set in Rx when the payload is ready (i.e. last byte
received and CRC, if enabled and CrcAutoClearOff is
cleared, is Ok). Cleared when FIFO is empty.
Set in Rx when the CRC of the payload is Ok. Cleared
when FIFO is empty.
Set when the battery voltage drops below the Low Battery
threshold. Cleared only when set by the user.
RSSI trigger level for Rssi interrupt :
- RssiThreshold / 2 [dBm]
Timeout interrupt is generated TimeoutRxStart*16*Tbit
after switching to Rx mode if Rssi interrupt doesn’t occur
(i.e. RssiValue > RssiThreshold)
0x00: TimeoutRxStart is disabled
Timeout interrupt is generated TimeoutRssiThresh*16*Tbit
after Rssi interrupt if PayloadReady interrupt doesn’t
occur.
0x00: TimeoutRssiThresh is disabled
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SX1231J
WIRELESS & SENSING
DATASHEET
4.6. Packet Engine Registers
Table 14 Packet Engine Registers
Name
(Address)
Bits Variable Name
Mode
Default
Description
Value
0x00 Size of the preamble to be sent (from TxStartCondition
fulfilled). (MSB byte)
RegPreambleMsb
(0x2c)
7-0
PreambleSize(15:8)
rw
RegPreambleLsb
(0x2d)
7-0
PreambleSize(7:0)
rw
0x03
7
SyncOn
rw
1
6
FifoFillCondition
rw
0
5-3
SyncSize
rw
011
2-0
7-0
SyncTol
SyncValue(63:56)
rw
rw
000
0x01
*
RegSyncValue2
(0x30)
7-0
SyncValue(55:48)
rw
0x01
*
2nd byte of Sync word
Used if SyncOn is set and (SyncSize +1) >= 2.
RegSyncValue3
(0x31)
7-0
SyncValue(47:40)
rw
0x01
*
3rd byte of Sync word.
Used if SyncOn is set and (SyncSize +1) >= 3.
RegSyncValue4
(0x32)
7-0
SyncValue(39:32)
rw
0x01
*
4th byte of Sync word.
Used if SyncOn is set and (SyncSize +1) >= 4.
RegSyncValue5
(0x33)
7-0
SyncValue(31:24)
rw
0x01
*
5th byte of Sync word.
Used if SyncOn is set and (SyncSize +1) >= 5.
RegSyncValue6
(0x34)
7-0
SyncValue(23:16)
rw
0x01
*
6th byte of Sync word.
Used if SyncOn is set and (SyncSize +1) >= 6.
RegSyncValue7
(0x35)
7-0
SyncValue(15:8)
rw
0x01
*
7th byte of Sync word.
Used if SyncOn is set and (SyncSize +1) >= 7.
RegSyncValue8
(0x36)
7-0
SyncValue(7:0)
rw
0x01
*
8th byte of Sync word.
Used if SyncOn is set and (SyncSize +1) = 8.
RegSyncConfig
(0x2e)
RegSyncValue1
(0x2f)
Rev 2 - April 2012
Page 24
Size of the preamble to be sent (from TxStartCondition
fulfilled). (LSB byte)
Enables the Sync word generation and detection:
0 Æ Off
1 Æ On
FIFO filling condition:
0 Æ if SyncAddress interrupt occurs
1 Æ as long as FifoFillCondition is set
Size of the Sync word:
(SyncSize + 1) bytes
Number of tolerated bit errors in Sync word
1st byte of Sync word. (MSB byte)
Used if SyncOn is set.
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PacketFormat
rw
0
6-5
DcFree
rw
00
4
CrcOn
rw
1
3
CrcAutoClearOff
rw
0
2-1
AddressFiltering
rw
00
0
7-0
PayloadLength
rw
rw
0
0x40
RegNodeAdrs
(0x39)
7-0
NodeAddress
rw
0x00
Defines the packet format used:
0 Æ Fixed length
1 Æ Variable length
Defines DC-free encoding/decoding performed:
00 Æ None (Off)
01 Æ Manchester
10 Æ Whitening
11 Æ reserved
Enables CRC calculation/check (Tx/Rx):
0 Æ Off
1 Æ On
Defines the behavior of the packet handler when CRC
check fails:
0 Æ Clear FIFO and restart new packet reception. No
PayloadReady interrupt issued.
1 Æ Do not clear FIFO. PayloadReady interrupt issued.
Defines address based filtering in Rx:
00 Æ None (Off)
01 Æ Address field must match NodeAddress
10 Æ Address field must match NodeAddress or
BroadcastAddress
11 Æ reserved
unused
If PacketFormat = 0 (fixed), payload length.
If PacketFormat = 1 (variable), max length in Rx, not used
in Tx.
Node address used in address filtering.
RegBroadcastAdrs
(0x3A)
7-0
BroadcastAddress
rw
0x00
Broadcast address used in address filtering.
RegAutoModes
(0x3B)
7-5
EnterCondition
rw
000
4-2
ExitCondition
rw
000
1-0
IntermediateMode
rw
00
Interrupt condition for entering the intermediate mode:
000 Æ None (AutoModes Off)
001 Æ Rising edge of FifoNotEmpty
010 Æ Rising edge of FifoLevel
011 Æ Rising edge of CrcOk
100 Æ Rising edge of PayloadReady
101 Æ Rising edge of SyncAddress
110 Æ Rising edge of PacketSent
111 Æ Falling edge of FifoNotEmpty (i.e. FIFO empty)
Interrupt condition for exiting the intermediate mode:
000 Æ None (AutoModes Off)
001 Æ Falling edge of FifoNotEmpty (i.e. FIFO empty)
010 Æ Rising edge of FifoLevel or Timeout
011 Æ Rising edge of CrcOk or Timeout
100 Æ Rising edge of PayloadReady or Timeout
101 Æ Rising edge of SyncAddress or Timeout
110 Æ Rising edge of PacketSent
111 Æ Rising edge of Timeout
Intermediate mode:
00 Æ Sleep mode (SLEEP)
01 Æ Standby mode (STDBY)
10 Æ Receiver mode (RX)
11 Æ Transmitter mode (TX)
RegPacketConfig1
(0x37)
RegPayloadLength
(0x38)
Rev 2 - April 2012
7
DATASHEET
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SX1231J
WIRELESS & SENSING
RegFifoThresh
(0x3C)
RegPacketConfig2
(0x3D)
7
DATASHEET
TxStartCondition
rw
FifoThreshold
InterPacketRxDelay
rw
rw
3
2
RestartRx
rw
w
1
AutoRxRestartOn
rw
0
AesOn
rw
6-0
7-4
1
*
Defines the condition to start packet transmission :
0 Æ FifoLevel (i.e. the number of bytes in the FIFO
exceeds FifoThreshold)
1 Æ FifoNotEmpty (i.e. at least one byte in the FIFO)
0001111 Used to trigger FifoLevel interrupt.
0000 After PayloadReady occurred, defines the delay between
FIFO empty and the start of a new RSSI phase for next
packet. Must match the transmitter’s PA ramp-down time.
- Tdelay = 0 if InterpacketRxDelay >= 12
- Tdelay = (2InterpacketRxDelay) / BitRate otherwise
0
unused
0
Forces the Receiver in WAIT mode, in Continuous Rx
mode.
Always reads 0.
1
Enables automatic Rx restart (RSSI phase) after
PayloadReady occurred and packet has been completely
read from FIFO:
0 Æ Off. RestartRx can be used.
1 Æ On. Rx automatically restarted after
InterPacketRxDelay.
0
Enable the AES encryption/decryption:
0 Æ Off
1 Æ On (payload limited to 66 bytes maximum)
0x00 1st byte of cipher key (MSB byte)
RegAesKey1
(0x3E)
7-0
AesKey(127:120)
w
RegAesKey2
(0x3F)
7-0
AesKey(119:112)
w
0x00
2nd byte of cipher key
RegAesKey3
(0x40)
7-0
AesKey(111:104)
w
0x00
3rd byte of cipher key
RegAesKey4
(0x41)
7-0
AesKey(103:96)
w
0x00
4th byte of cipher key
RegAesKey5
(0x42)
7-0
AesKey(95:88)
w
0x00
5th byte of cipher key
RegAesKey6
(0x43)
7-0
AesKey(87:80)
w
0x00
6th byte of cipher key
RegAesKey7
(0x44)
7-0
AesKey(79:72)
w
0x00
7th byte of cipher key
RegAesKey8
(0x45)
7-0
AesKey(71:64)
w
0x00
8th byte of cipher key
RegAesKey9
(0x46)
7-0
AesKey(63:56)
w
0x00
9th byte of cipher key
RegAesKey10
(0x47)
7-0
AesKey(55:48)
w
0x00
10th byte of cipher key
RegAesKey11
(0x48)
7-0
AesKey(47:40)
w
0x00
11th byte of cipher key
RegAesKey12
(0x49)
7-0
AesKey(39:32)
w
0x00
12th byte of cipher key
RegAesKey13
(0x4A)
7-0
AesKey(31:24)
w
0x00
13th byte of cipher key
Rev 2 - April 2012
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SX1231J
WIRELESS & SENSING
DATASHEET
RegAesKey14
(0x4B)
7-0
AesKey(23:16)
w
0x00
14th byte of cipher key
RegAesKey15
(0x4C)
7-0
AesKey(15:8)
w
0x00
15th byte of cipher key
RegAesKey16
(0x4D)
7-0
AesKey(7:0)
w
0x00
16th byte of cipher key (LSB byte)
4.7. Temperature Sensor Registers
Table 15 Temperature Sensor Registers
Name
(Address)
Bits Variable Name
RegTemp1
(0x4E)
7-4
3
2
RegTemp2
(0x4F)
1-0
7-0
Mode
TempMeasStart
r
w
TempMeasRunning
r
TempValue
r
r
Default
Description
Value
0000 unused
0
Triggers the temperature measurement when set. Always
reads 0.
0
Set to 1 while the temperature measurement is running.
Toggles back to 0 when the measurement has completed.
The receiver can not be used while measuring
temperature
01
unused
Measured temperature
-1°C per Lsb
Needs calibration for accuracy
4.8. Test Registers
Table 16 Test Registers
Name
(Address)
RegTestLna
(0x58)
Bits Variable Name
Mode
7-0
SensitivityBoost
rw
RegTestTcxo
(0x59)
7-0
TcxoOn
rw
RegTestDagc
(0x6F)
7-0
ContinuousDagc
rw
RegTestAfc
(0x71)
7-0
LowBetaAfcOffset
rw
Rev 2 - April 2012
Default
Description
Value
0x1B High sensitivity or normal sensitivity mode:
0x1B Æ Normal mode
0x2D Æ High sensitivity mode
0x09 Selects XTAL or TCXO input:
0x09 Æ Normal XTAL mode
0x19 Æ Clipped sine TCXO input
0x30 Fading Margin Improvement, refer to 3.5.4
*
0x00 Æ Normal mode
0x20 Æ Improved margin, use if AfcLowBetaOn=1
0x30 Æ Improved margin, use if AfcLowBetaOn=0
0x00 AFC offset set for low modulation index systems, used if
AfcLowBetaOn=1.
Offset = LowBetaAfcOffset x 488 Hz
Page 27
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SX1231J
WIRELESS & SENSING
DATASHEET
5. Application Information
Application information shown here is SX1231J-specific. More application information relevant to the SX1231J can be
found in [1].
5.1. Reference Design
Please contact your Semtech representative for evaluation tools, reference designs and design assistance. Note that all
schematics shown in this section are full schematics, listing ALL required components, including decoupling capacitors.
L3
C5
L4
C3
L2
C6
L1
R6
C7
C4
VBAT1
C2
C22
GND
GND
GND
U2
C19
OPT1
C20
VDD
GND
Input
OPT2
Vcont
C21
GND
R7
J1
UPG2010TB
C23
C17
L5
C8
GND
GND
C18
GND
GND
GND
GND
RXTX
VBAT1
VBAT1
R1
GND1
Shorted_res
C1
10uF
GND
GND
19
20
GND
RXTX
21
22
GND
RFIO
SCK
GND
RESET
CLKOUT
XTB
DIO4
R5
GND
GND
VBAT2
P1
18
1
2
17
Header 2
16
POD_IN1
15
14
13
VBAT2
GND
C15
100nF
12
C12
100nF
25
11
TXCO-32MHz
C11
100nF
MISO
DIO3
6
C14
VR_DIG
XTA
GND
GND
NSS
DIO2
Out
3
R2 Shorted_res
MOSI
9
4
Vcc
EN
2
R4
5
GND
1
GND
4
Q1
VBAT2
SX1231J
VR_ANA
10
C13
Vcon
24
VR_PA
3
VBAT1
DIO1
2
VBAT1
DIO0
1
7
GND
8
C10
100nF
PA_BOOST
U1
23
GND2
1
3
5
7
9
11
13
15
17
19
2
4
6
8
10
12
14
16
18
20
VDD
GND
DIO3
MISO
RESET
DIO0
NC
NC
NC
Vcon
GND
Header 10X2
GND
GND
SCK
MOSI
DIO1
NSS
CLKOUT
DIO4
RXTX
DIO1
DIO2
NC
GND
R3
0R
Figure 4. SX1231J Evaluation Module Schematics
Rev 2 - April 2012
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SX1231J
WIRELESS & SENSING
DATASHEET
Table 17 SX1231J Evaluation Module BOM
Notes - Inductor values may change when using multilayer type components, but nearly equal performance should be
attained
- In very cost-sensitive and/or size-constrained applications where it is acceptable to degrade the receiver
sensitivity, L5 and C17 and C18 can be omitted
Rev 2 - April 2012
Page 29
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SX1231J
WIRELESS & SENSING
DATASHEET
5.2. Regulatory Compliance
The SX1231J performance is such that it complies with narrowband and wideband Japanese regulations. This is mostly
achieved thanks to the excellent spectral purity and best in-class Local Oscillator phase noise.
5.2.1. ARIB STD-T67
The ARIB STD-T67 standard mandates narrow 12.5kHz channels at about 426, 449 and 469MHz. With the proposed
reference design, Semtech recommends the following RF settings:
Š
Š
Š
Š
GFSK modulation, with BT=0.5
Bit Rate = 2.4 kbps, Fdev = +/-3 kHz
RxBw = 5.2 kHz, corresponding to a double side bandwidth of 10.4 kHz
Pout = +10 mW, as limited by STD-T67
Under these conditions, the SX1231J fulfills all the requirements of the STD-T67 with significant margin, namely:
Š
Š
Š
Š
Š
Š
99% energy bandwidth is lower than 8.5 kHz
Spurious emissions meet the -26 dBm limit with more than 20 dB of margin
Adjacent Channel leakage power with more than 15 dB margin
The observed sensitivity is typ. -118 dBm with BER=0.1%, and -120 dBm with BER=1%
Spurious response rejection does not apply with SX1231J’s Direct Conversion architecture
At 12.5 kHz and 25 kHz offsets, the typical selectivity is respectively 36dB and 57dB (requirement: 30dB), and can be
improved to typ. 55dB, respectively 59dB with the use of a tighter internal Channel Filter (RxBw=3.9 kHz). Using a
narrower filter increases the constraint on the Local Oscillator stability accordingly (TCXO performance).
Other sets of bit rates and deviation frequencies may of course be possible.
5.2.2. ARIB STD-T108
The ARIB STD-T108 standard focuses on wider channels of 200 kHz or more in the 915-930 MHz band. Under these
conditions, there is more flexibility as to the choice of the RF settings.
The SX1231J will fulfill the requirements of the STD-T108 in Middle Power (up to 250mW), Low Power (up to 20mW) and
Ultra Low Power (up to 1mW) modes. An external Power Amplifier will be required to increase the output power over
+17dBm. With its spectral purity, the SX1231J can meet the 99% energy bandwidth, spectral mask, Adjacent Channel
Leakage Power and Spurious emissions limits of the standard with significant margin.
In particular, the SX1231J complies with the radio Type 1 (+13dBm) constraints for Smart Metering and Sensor Networks
applications, under the Common Signaling Mode as defined in the IEEE 802.15.4g.
Please contact your local Semtech representative for a detailed report on the STD-T67 or STD-T108 compliance of the
SX1231J.
Rev 2 - April 2012
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SX1231J
WIRELESS & SENSING
DATASHEET
6. Packaging Information
6.1. QFN 24 Encapsulation
The SX1231J is available in a 24-lead QFN package as show in Figure 5.
A
DIMENSIONS
MILLIMETERS
MIN NOM MAX
B
D
DIM
E
PIN 1
INDICATOR
(LASER MARK)
A1
A2
A
SEATING
PLANE
aaa C
A
A1
A2
b
D
D1
E
E1
e
L
N
aaa
bbb
0.80 1.00
0.00
0.05
- (0.20) 0.25 0.30 0.35
4.90 5.00 5.10
3.20 3.25 3.30
4.90 5.00 5.10
3.20 3.25 3.30
0.65 BSC
0.35 0.40 0.45
24
0.08
0.10
C
LxN
D1
E/2
E1
2
1
N
bxN
e/2
bbb
C A B
e
D/2
NOTES:
1. CONTROLLING DIMENSIONS ARE IN MILLIMETERS (ANGLES IN DEGREES).
2. COPLANARITY APPLIES TO THE EXPOSED PAD AS WELL AS THE TERMINALS.
Figure 5. QFN 24 Package Outline Drawing and Land Pattern
6.2. Thermal Impedance
The thermal impedance of this package, calculated from a package in still air, on a 4-layer FR4 PCB, as per the Jedec
standard, is Theta ja = 23.8° C/W typ.
Rev 2 - April 2012
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WIRELESS & SENSING
DATASHEET
6.3. Tape & Reel Specification
Figure 6. Tape & Reel Specification, QFN Package
Note
Single Sprocket holes
Rev 2 - April 2012
Page 32
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SX1231J
WIRELESS & SENSING
DATASHEET
7. References
[1]
SX1231 Datasheet. Please consult the Semtech website www.semtech.com on a regular basis for news and updates.
8. Revision History
Table 18 Revision History
Revision
1
Date
Jan 2012
2
April 2012
Rev 2 - April 2012
Comment
First FINAL datasheet version
Minor edits
Mention STD-T108
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SX1231J
WIRELESS & SENSING
DATASHEET
© Semtech 2012
All rights reserved. Reproduction in whole or in part is prohibited without the prior written consent of the copyright owner. The
information presented in this document does not form part of any quotation or contract, is believed to be accurate and reliable
and may be changed without notice. No liability will be accepted by the publisher for any consequence of its use. Publication
thereof does not convey nor imply any license under patent or other industrial or intellectual property rights. Semtech assumes
no responsibility or liability whatsoever for any failure or unexpected operation resulting from misuse, neglect improper
installation, repair or improper handling or unusual physical or electrical stress including, but not limited to, exposure to
parameters beyond the specified maximum ratings or operation outside the specified range.
SEMTECH PRODUCTS ARE NOT DESIGNED, INTENDED, AUTHORIZED OR WARRANTED TO BE SUITABLE FOR USE IN
LIFE-SUPPORT APPLICATIONS, DEVICES OR SYSTEMS OR OTHER CRITICAL APPLICATIONS. INCLUSION OF
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Contact information
Semtech Corporation
Wireless & Sensing Products Division
200 Flynn Road, Camarillo, CA 93012
Phone: (805) 498-2111 Fax: (805) 498-3804
E-mail: [email protected]
[email protected]
Internet: http://www.semtech.com
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