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Semtech |
SX1272/73
WIRELESS, SENSING & TIMING
DATASHEET
SX1272/73 - 860 MHz to 1020 MHz Low Power Long Range Transceiver
GENERAL DESCRIPTION
The SX1272/73 transceivers feature the LoRaTM long range
modem that provides ultra-long range spread spectrum
communication and high interference immunity whilst
minimising current consumption.
Using Semtech’s patented LoRaTM modulation technique
SX1272/73 can achieve a sensitivity of over -137 dBm using
a low cost crystal and bill of materials. The high sensitivity
combined with the integrated +20 dBm power amplifier
yields industry leading link budget making it optimal for any
application requiring range or robustness. LoRaTM also
provides significant advantages in both blocking and
selectivity over conventional modulation techniques, solving
the traditional design compromise between range,
interference immunity and energy consumption.
These devices also support high performance (G)FSK
modes for systems including WMBus, IEEE802.15.4g. The
SX1272/73 deliver exceptional phase noise, selectivity,
receiver linearity and IIP3 for significantly lower current
consumption than competing devices.
ORDERING INFORMATION
Part Number
SX1272IMLTRT
SX1273IMLTRT
Delivery
T&R
T&R
MOQ / Multiple
3000 pieces
3000 pieces
QFN 28 Package - Operating Range from -40 to +85°C
Pb-free, Halogen free, RoHS/WEEE compliant product
KEY PRODUCT FEATURES
LoRaTM Modem
157 dB maximum link budget
+20 dBm at 100 mW constant RF output vs. V supply
+14 dBm high efficiency PA
Programmable bit rate up to 300 kbps
High sensitivity: down to -137 dBm
Bullet-proof front end: IIP3 = -12.5 dBm
89 dB blocking immunity
Low RX current of 10 mA, 100 nA register retention
Fully integrated synthesizer with a resolution of 61 Hz
FSK, GFSK, MSK, GMSK, LoRaTM and OOK modulation
Built-in bit synchronizer for clock recovery
Preamble detection
127 dB Dynamic Range RSSI
Automatic RF Sense and CAD with ultra-fast AFC
Packet engine up to 256 bytes with CRC
Built-in temperature sensor and low battery indicator
APPLICATIONS
Automated Meter Reading
Home and Building Automation
Wireless Alarm and Security Systems
Industrial Monitoring and Control
Long range Irrigation Systems
Rev. 3 - March 2015
©2015 Semtech Corporation
Page 1
www.semtech.com
WIRELESS, SENSING & TIMING
Table of contents
Section
SX1272/73
DATASHEET
Page
1. General Description ............................................................................................................................................... 10
1.1. Simplified Block Diagram ............................................................................................................................... 10
1.2. Product Versions ............................................................................................................................................11
1.3. Pin Diagram ................................................................................................................................................... 11
1.4. Pin Description ...............................................................................................................................................12
1.5. Package Marking ...........................................................................................................................................13
2. Electrical Characteristics ....................................................................................................................................... 14
2.1. ESD Notice .................................................................................................................................................... 14
2.2. Absolute Maximum Ratings ........................................................................................................................... 14
2.3. Operating Range............................................................................................................................................ 14
2.4. Thermal Properties ........................................................................................................................................ 14
2.5. Chip Specification ..........................................................................................................................................15
2.5.1. Power Consumption .................................................................................................................................. 15
2.5.2. Frequency Synthesis................................................................................................................................. 15
2.5.3. FSK/OOK Mode Receiver ......................................................................................................................... 16
2.5.4. FSK/OOK Mode Transmitter ..................................................................................................................... 17
2.5.5. Electrical specification for LoRaTM modulation ........................................................................................ 18
2.5.6. Digital Specification ................................................................................................................................... 20
3. SX1272/73 Features.............................................................................................................................................. 21
3.1. LoRaTM Modem ............................................................................................................................................ 22
3.2. FSK/OOK Modem .......................................................................................................................................... 22
4. SX1272/73 Digital Electronics ............................................................................................................................... 23
4.1. The LoRaTM Modem ..................................................................................................................................... 23
4.1.1. Link Design Using the LoRaTM Modem ....................................................................................................24
4.1.1.1. Overview ........................................................................................................................................... 24
4.1.1.2. Spreading Factor............................................................................................................................... 25
4.1.1.3. Coding Rate ...................................................................................................................................... 25
4.1.1.4. Signal Bandwidth .............................................................................................................................. 26
4.1.1.5. LoRaTM Transmission Parameter Relationship ............................................................................... 26
4.1.1.6. LoRaTM Packet Structure .................................................................................................................27
4.1.1.7. Time on air ........................................................................................................................................ 29
4.1.1.8. Frequency Hopping with LoRaTM..................................................................................................... 29
4.1.2. LoRaTM Digital Interface ...........................................................................................................................31
4.1.2.1. LoRaTM Configuration Registers ...................................................................................................... 31
4.1.2.2. Status Registers................................................................................................................................ 31
4.1.2.3. LoRaTM Mode FIFO Data Buffer ...................................................................................................... 31
4.1.2.4. Interrupts in LoRa Mode.................................................................................................................... 32
4.1.3. Operation of the LoRaTM Modem............................................................................................................. 33
4.1.3.1. Operating Mode Control .................................................................................................................... 33
4.1.4. Frequency Settings ...................................................................................................................................34
4.1.5. Frequency Error Indication ........................................................................................................................ 34
4.1.6. LoRaTM Modem State Machine Sequences .............................................................................................35
Rev. 3 - March 2015
©2015 Semtech Corporation
Page 2
www.semtech.com
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