SX1276/77/79

Part: SX1276/77/78/79 — Semtech

Type: Sub-GHz LoRa / FSK / OOK Transceiver

Description: 137–1020 MHz low-power long-range transceiver with LoRa modem, sensitivity down to -148 dBm, +20 dBm PA, 168 dB maximum link budget and bit rates up to 300 kbps.

Operating Conditions:

• Supply voltage: -0.5 to 3.9 V is the absolute maximum; the recommended operating-range table is not included in the provided text
• Operating temperature: -40 to +85 °C (QFN 28 package operating range)
• Frequency range: 137–1020 MHz
• Programmable bit rate: up to 300 kbps

Absolute Maximum Ratings:

• Max supply voltage (VDDmr): 3.9 V (min -0.5 V)
• Max junction temperature (Tj): +125 °C
• Temperature (Tmr): -55 to +115 °C
• Max RF input level: +10 dBm

Key Specs:

• Receiver sensitivity: down to -148 dBm (LoRa)
• Maximum link budget: 168 dB
• RX current: 9.9 mA; register retention 200 nA
• Maximum RF output: +20 dBm (100 mW), constant vs. supply voltage
• High-efficiency PA: +14 dBm
• Input IP3: -11 dBm
• RSSI dynamic range: 127 dB
• Synthesizer resolution: 61 Hz

Features:

• LoRa modem for long-range spread spectrum communication
• FSK, GFSK, MSK, GMSK, LoRa and OOK modulation
• Built-in bit synchronizer for clock recovery
• Preamble detection
• 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
• Excellent blocking immunity
• Supports WMBus and IEEE 802.15.4g in (G)FSK modes

Applications:

• Automated meter reading
• Home and building automation
• Wireless alarm and security systems
• Industrial monitoring and control
• Long range irrigation systems

Package:

• QFN 28, Pb-free, halogen-free, RoHS/WEEE compliant
• Wafer form (SX1276WS)

• LoRa TM Modem
• 168 dB maximum link budget
• +20 dBm - 100 mW constant RF output vs. V supply
• +14 dBm high efficiency PA
• Programmable bit rate up to 300 kbps
• High sensitivity: down to -148 dBm
• Bullet-proof front end: IIP3 = -11 dBm
• Excellent blocking immunity
• Low RX current of 9.9 mA, 200 nA register retention
• Fully integrated synthesizer with a resolution of 61 Hz
• FSK, GFSK, MSK, GMSK, LoRa TM 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

• Automated Meter Reading.
• Home and Building Automation.
• Wireless Alarm and Security Systems.
• Industrial Monitoring and Control
• Long range Irrigation Systems

DATASHEET

• Section Section Page
• 1. General Description................................................................................................................................................. 9
• 1.1. Simplified Block Diagram................................................................................................................................. 9
• 1.2. Product Versions ............................................................................................................................................10
• 1.3. Pin Diagram ................................................................................................................................................... 10
• 1.4. Pin Description ...............................................................................................................................................11
• 1.5. Package Marking ...........................................................................................................................................12
• 1. Electrical Characteristics ....................................................................................................................................... 13
• 2.1. ESD Notice .................................................................................................................................................... 13
• 2.2. Absolute Maximum Ratings ........................................................................................................................... 13
• 2.3. Operating Range............................................................................................................................................ 13
• 2.4. Thermal Properties ........................................................................................................................................ 13
• 2.5. Chip Specification ..........................................................................................................................................14
• 2.5.1. Power Consumption.................................................................................................................................. 14
• 2.5.2. Frequency Synthesis................................................................................................................................. 14
• 2.5.3. FSK/OOK Mode Receiver .........................................................................................................................16
• 2.5.4. FSK/OOK Mode Transmitter ..................................................................................................................... 17
• 2.5.5. Electrical Specification for LoRaTM Modulation ........................................................................................19
• 2.5.6. Digital Specification ...................................................................................................................................22
• 1. SX1276/77/78/79 Features.................................................................................................................................... 23
• 3.1. LoRaTM Modem............................................................................................................................................ 24
• 3.2. FSK/OOK Modem.......................................................................................................................................... 24
• 1. SX1276/77/78/79 Digital Electronics ..................................................................................................................... 25
• 4.1. The LoRaTM Modem..................................................................................................................................... 25
• 4.1.1. Link Design Using the LoRaTM Modem ....................................................................................................26
• 4.1.2. LoRaTM Digital Interface ...........................................................................................................................34
• 4.1.3. Operation of the LoRaTM Modem............................................................................................................. 36
• 4.1.4. Frequency Settings ...................................................................................................................................37
• 4.1.5. Frequency Error Indication........................................................................................................................ 37
• 4.1.6. LoRaTM Modem State Machine Sequences .............................................................................................38
• 4.1.7. Modem Status Indicators........................................................................................................................... 46
• 4.2. FSK/OOK Modem.......................................................................................................................................... 46
• 4.2.1. Bit Rate Setting ......................................................................................................................................... 46
• 4.2.2. FSK/OOK Transmission............................................................................................................................ 47
• 4.2.3. FSK/OOK Reception ................................................................................................................................. 48
• 4.2.4. Operating Modes in FSK/OOK Mode........................................................................................................ 54
• 4.2.5. Startup Times ............................................................................................................................................56
• 4.2.6. Receiver Startup Options .......................................................................................................................... 59
• 4.2.7. Receiver Restart Methods......................................................................................................................... 60
• 4.2.8. Top Level Sequencer ................................................................................................................................ 61

DATASHEET

• Section Page
• 4.2.9. Data Processing in FSK/OOK Mode......................................................................................................... 65
• 4.2.10. FIFO ........................................................................................................................................................66
• 4.2.11. Digital IO Pins Mapping ...........................................................................................................................69
• 4.2.12. Continuous Mode ....................................................................................................................................70
• 4.2.13. Packet Mode ........................................................................................................................................... 71
• 4.2.14. io-homecontrol® Compatibility Mode ...................................................................................................... 79
• 4.3. SPI Interface ..................................................................................................................................................80
• SX1276/77/78/79 Analog & RF Frontend Electronics............................................................................................ 81
• 5.1. Power Supply Strategy .................................................................................................................................. 81
• 5.2. Low Battery Detector ..................................................................................................................................... 81
• 5.3. Frequency Synthesis ..................................................................................................................................... 81
• 5.3.1. Crystal Oscillator ....................................................................................................................................... 81
• 5.3.2. CLKOUT Output........................................................................................................................................ 82
• 5.3.3. PLL............................................................................................................................................................ 82
• 5.3.4. RC Oscillator ............................................................................................................................................. 82
• 5.4. Transmitter Description ..................................................................................................................................83
• 5.4.1. Architecture Description ............................................................................................................................ 83
• 5.4.2. RF Power Amplifiers.................................................................................................................................. 83
• 5.4.3. High Power +20 dBm Operation ............................................................................................................... 84
• 5.4.4. Over Current Protection ............................................................................................................................85
• 5.5. Receiver Description...................................................................................................................................... 85
• 5.5.1. Overview ................................................................................................................................................... 85
• 5.5.2. Receiver Enabled and Receiver Active States.......................................................................................... 85
• 5.5.3. Automatic Gain Control In FSK/OOK Mode.............................................................................................. 85
• 5.5.4. RSSI in FSK/OOK Mode........................................................................................................................... 86
• 5.5.5. RSSI and SNR in LoRaTM Mode.............................................................................................................. 87
• 5.5.6. Channel Filter ............................................................................................................................................ 88
• 5.5.7. Temperature Measurement....................................................................................................................... 89
• Description of the Registers................................................................................................................................... 90
• 6.1. Register Table Summary............................................................................................................................... 90
• 6.2. FSK/OOK Mode Register Map .......................................................................................................................93
• 6.3. Band Specific Additional Registers.............................................................................................................. 106
• 6.4. LoRaTM Mode Register Map....................................................................................................................... 108
• Application Information ........................................................................................................................................ 116
• 7.2. Reset of the Chip ......................................................................................................................................... 116
• 7.2.1. POR......................................................................................................................................................... 116
• 7.2.2. Manual Reset ..........................................................................................................................................117
• 7.3. Top Sequencer: Listen Mode Examples...................................................................................................... 117

DATASHEET

• Section Page
• 7.3.1. Wake on Preamble Interrupt ................................................................................................................... 117
• 7.3.2. Wake on SyncAddress Interrupt ..............................................................................................................120
• 7.4. Top Sequencer: Beacon Mode ....................................................................................................................123
• 7.4.1. Timing diagram........................................................................................................................................ 123
• 7.4.2. Sequencer Configuration......................................................................................................................... 123
• 7.5. Example CRC Calculation ...........................................................................................................................125
• 7.6. Example Temperature Reading ...................................................................................................................126
• 1. Packaging Information......................................................................................................................................... 128
• 8.1. Package Outline Drawing ............................................................................................................................ 128
• 8.2. Recommended Land Pattern....................................................................................................................... 129
• 8.3. Tape & Reel Information.............................................................................................................................. 130
• 8.4. Wafer Delivery ............................................................................................................................................. 130

Table 2 Pin Description WIRELESS, SENSING & TIMING

DATASHEET

Stresses above the values listed below may cause permanent device failure. Exposure to absolute maximum ratings for extended periods may affect device reliability.

Table 3 Absolute Maximum Ratings

Note Specific ratings apply to +20 dBm operation (see Section 5.4.3).

Table 5 Thermal Properties

Table 5 Thermal Properties

DATASHEET

The SX1276/77/78/79 is available in a 28-lead QFN package as shown in Figure 57.

Figure 57. Package Outline Drawing

DATASHEET