SX1276
SX1276/77/78/79 - 137 MHz to 1020 MHz Low Power Long Range Transceiver
Manufacturer
unknown
Overview
Part: SX1276/77/78/79 from Semtech
Type: Low Power Long Range Transceiver
Key Specs:
- Frequency range: 137 MHz to 1020 MHz
- Maximum link budget: 168 dB
- Constant RF output power: +20 dBm (100 mW)
- High efficiency PA output: +14 dBm
- Programmable bit rate: up to 300 kbps
- High sensitivity: down to -148 dBm
- IIP3: -11 dBm
- Low RX current: 9.9 mA
- Register retention current: 200 nA
- Synthesizer resolution: 61 Hz
- Dynamic Range RSSI: 127 dB
Features:
- LoRaTM Modem
- Constant RF output vs. V supply
- Excellent blocking immunity
- Fully integrated synthesizer
- FSK, GFSK, MSK, GMSK, LoRaTM 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
Applications:
- Automated Meter Reading
- Home and Building Automation
- Wireless Alarm and Security Systems
- Industrial Monitoring and Control
- Long range Irrigation Systems
Package:
- QFN 28 Package: null
Features
- LoRaTM 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, LoRaTMand 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
Pin Configuration
Table 2 Pin Description
| Number | Name | Type | Description |
|---|---|---|---|
| SX1276/77/79/(78) | SX1276/77/79/(78) | SX1276/77/79/(78) | |
| 0 | GROUND | - | Exposed ground pad |
| 1 | RFI_LF | I | RF input for bands 2&3 |
| 2 | VR_ANA | - | Regulated supply voltage for analogue circuitry |
| 3 | VBAT_ANA | - | Supply voltage for analogue circuitry |
| 4 | VR_DIG | - | Regulated supply voltage for digital blocks |
| 5 | XTA | I/O | XTAL connection or TCXO input |
| 6 | XTB | I/O | XTAL connection |
| 7 | NRESET | I/O | Reset trigger input |
| 8 | DIO0 | I/O | Digital I/O, software configured |
| 9 | DIO1/DCLK | I/O | Digital I/O, software configured |
| 10 | DIO2/DATA | I/O | Digital I/O, software configured |
| 11 | DIO3 | I/O | Digital I/O, software configured |
| 12 | DIO4 | I/O | Digital I/O, software configured |
| 13 | DIO5 | I/O | Digital I/O, software configured |
| 14 | VBAT_DIG | - | Supply voltage for digital blocks |
| 15 | GND | - | Ground |
| 16 | SCK | I | SPI Clock input |
| 17 | MISO | O | SPI Data output |
| 18 | MOSI | I | SPI Data input |
| 19 | NSS | I | SPI Chip select input |
| 20 | RXTX/RF_MOD | O | Rx/Tx switch control: high in Tx |
| 21 | RFI_HF (GND) | I (-) | RF input for band 1 (Ground) |
| 22 | RFO_HF (GND) | O (-) | RF output for band 1 (Ground) |
| 23 | GND | - | Ground |
| 24 | VBAT_RF | - | Supply voltage for RF blocks |
| 25 | VR_PA | - | Regulated supply for the PA |
| 26 | GND | - | Ground |
| 27 | PA_BOOST | O | Optional high-power PA output, all frequency bands |
| 28 | RFO_LF | O | RF output for bands 2&3 |
1.5. Package Marking
| TOP MARK | |-----------|------|--| | CHAR | ROWS | | 7/7/7/7/7 | 5 |
Figure 3. Marking Diagram
Electrical Characteristics
2.1. ESD Notice
The SX1276/77/78/79 is a high performance radio frequency device. It satisfies:
- Class 2 of the JEDEC standard JESD22-A114 (Human Body Model) on all pins.
- Class III of the JEDEC standard JESD22-C101 (Charged Device Model) on all pins
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
| 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 | - | +10 | dBm |
Note Specific ratings apply to +20 dBm operation (see Section 5.4.3).
2.3. Operating Range
Table 4 Operating Range
| Symbol | Description | Min | Max | Unit |
|---|---|---|---|---|
| VDDop | Supply voltage | 1.8 | 3.7 | V |
| Top | Operational temperature range | -40 | +85 | °C |
| Clop | Load capacitance on digital ports | - | 25 | pF |
| ML | RF Input Level | - | +10 | dBm |
Note A specific supply voltage range applies to +20 dBm operation (see Section 5.4.3).
2.4. Thermal Properties
©2016 Semtech Corporation
Table 5 Thermal Properties
| Symbol | Description | Min | Typ | Max | Unit |
|---|---|---|---|---|---|
| THETA_JA | Package θja (Junction to ambient) | - | 22.185 | - | °C/W |
| THETA_JC | Package θjc (Junction to case ground paddle) | - | 0.757 | - | °C/W |
2.5. Chip Specification
The tables below give the electrical specifications of the transceiver under the following conditions: Supply voltage VDD=3.3 V, temperature = 25 °C, FXOSC = 32 MHz, FRF = 169/434/868/915 MHz (see specific indication), 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, shared Rx and Tx path matching, unless otherwise specified.
Note Specification whose symbol is appended with "_LF" corresponds to the performance in Band 2 and/or Band 3, as described in section 5.3.3. "_HF" refers to the upper Band 1
2.5.1. Power Consumption
Table 6 Power Consumption Specification
| Symbol | Description | Conditions | Min | Typ | Max | Unit |
|---|---|---|---|---|---|---|
| IDDSL | Supply current in Sleep mode | - | 0.2 | 1 | uA | |
| IDDIDLE | Supply current in Idle mode | RC oscillator enabled | - | 1.5 | - | uA |
| IDDST | Supply current in Standby mode | Crystal oscillator enabled | - | 1.6 | 1.8 | mA |
| IDDFS | Supply current in Synthesizer mode | FSRx | - | 5.8 | - | mA |
| IDDR | Supply current in Receive mode | LnaBoost Off, band 1 LnaBoost On, band 1 Bands 2&3 | - - - | 10.8 11.5 12.0 | - - - | mA |
| IDDT | Supply current in Transmit mode with impedance matching | RFOP = +20 dBm, on PA_BOOST RFOP = +17 dBm, on PA_BOOST RFOP = +13 dBm, on RFO_LF/HF pin RFOP = + 7 dBm, on RFO_LF/HF pin | - - - - | 120 87 29 20 | - - - - | mA mA mA mA |
2.5.2. Frequency Synthesis
Table 7 Frequency Synthesizer Specification
| Symbol | Description | Conditions | Min | Typ | Max | Unit | |
|---|---|---|---|---|---|---|---|
| FR | Synthesizer frequency range | Programmable (*for SX1279) | Band 3 Band 2 Band 1 | 137 410 862 (*779) | - - - | 175 (*160) 525 (*480) 1020 (*960) | MHz |
| FXOSC | Crystal oscillator frequency | - | 32 | - | MHz | ||
| TS_OSC | Crystal oscillator wake-up time | - | 250 | - | us | ||
| TS_FS | Frequency synthesizer wake-up time to PllLock signal | From Standby mode | - | 60 | - | us |
| TS_HOP | Frequency synthesizer hop time at most 10 kHz away from the target frequency | 200 kHz step 1 MHz step 5 MHz step 7 MHz step 12 MHz step 20 MHz step 25 MHz step | - - - - - - - | 20 20 50 50 50 50 50 | - - - - - - - | us us us us us us us |
|---|---|---|---|---|---|---|
| FSTEP | Frequency synthesizer step | FSTEP = FXOSC/219 | - | 61.0 | - | Hz |
| FRC | RC Oscillator frequency | After calibration | - | 62.5 | - | kHz |
| BRF | Bit rate, FSK | Programmable values (1) | 1.2 | - | 300 | kbps |
| BRA | Bit rate Accuracy, FSK | ABS(wanted BR - available BR) | - | - | 250 | ppm |
| BRO | Bit rate, OOK | Programmable | 1.2 | - | 32.768 | kbps |
| BR_L | Bit rate, LoRa Mode | From SF6, BW=500kHz to SF12, BW=7.8kHz | 0.018 | - | 37.5 | kbps |
| FDA | Frequency deviation, FSK (1) | Programmable FDA + BRF/2 =< 250 kHz | 0.6 | - | 200 | kHz |
Note: For Maximum Bit rate, the maximum modulation index is 0.5.
2.5.3. FSK/OOK Mode Receiver
All receiver tests are performed with RxBw = 10 kHz (Single Side Bandwidth) as programmed in RegRxBw, receiving a PN15 sequence. Sensitivities are reported for a 0.1% BER (with Bit Synchronizer enabled), unless otherwise specified. 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 receiver sensitivity level.
Table 8 FSK/OOK Receiver Specification
| Symbol | Description | Conditions | Min | Typ | Max | Unit |
|---|---|---|---|---|---|---|
| Direct tie of RFI and RFO pins, shared Rx, Tx paths FSK sensitiv ity, highest LNA gain. Bands 2&3 | FDA = 5 kHz, BR = 1.2 kb/s FDA = 5 kHz, BR = 4.8 kb/s FDA = 40 kHz, BR = 38.4 kb/s* FDA = 20 kHz, BR = 38.4 kb/s** FDA = 62.5 kHz, BR = 250 kb/s*** | - - - - - | -121 -117 -107 -108 -95 | - - - - - | dBm dBm dBm dBm dBm | |
| RFS_F_LF | Split RF paths, the RF switch insertion loss is not accounted for. Bands 2&3 | FDA = 5 kHz, BR = 1.2 kb/s FDA = 5 kHz, BR = 4.8 kb/s FDA = 40 kHz, BR = 38.4 kb/s* FDA = 20 kHz, BR = 38.4 kb/s** FDA = 62.5 kHz, BR = 250 kb/s*** | - - - - - | -123 -119 -109 -110 -97 | - - - - - | dBm dBm dBm dBm dBm |
| Direct tie of RFI and RFO pins, shared Rx, Tx paths FSK sensitiv ity, highest LNA gain. Band 1 | FDA = 5 kHz, BR = 1.2 kb/s FDA = 5 kHz, BR = 4.8 kb/s FDA = 40 kHz, BR = 38.4 kb/s* FDA = 20 kHz, BR = 38.4 kb/s** FDA = 62.5 kHz, BR = 250 kb/s*** | - - - - - | -119 -115 -105 -105 -92 | - - - - - | dBm dBm dBm dBm dBm | |
| RFS_F_HF | Split RF paths, LnaBoost is turned on, the RF switch insertion loss is not accounted for. Band 1 | FDA = 5 kHz, BR = 1.2 kb/s FDA = 5 kHz, BR = 4.8 kb/s FDA = 40 kHz, BR = 38.4 kb/s* FDA = 20 kHz, BR = 38.4 kb/s** FDA = 62.5 kHz, BR = 250 kb/s*** | - - - - - | -123 -119 -109 -109 -96 | - - - - - | dBm dBm dBm dBm dBm |
| RFS_O | OOK sensitivity, highest LNA gain shared Rx, Tx paths | BR = 4.8 kb/s BR = 32 kb/s | - - | -117 -108 | - - | dBm dBm |
| CCR | Co-Channel Rejection, FSK | - | -9 | - | dB | |
| ACR | Adjacent Channel Rejection | FDA = 5 kHz, BR=4.8kb/s Offset = +/- 25 kHz or +/- 50kHz Band 1 Band 2 Band 3 | - - - | 50 56 60 | - - - | dB dB dB |
| BI_HF | Blocking Immunity, Band 1 | Offset = +/- 1 MHz Offset = +/- 2 MHz Offset = +/- 10 MHz | - - - | 71 76 84 | - - - | dB dB dB |
| BI_LF | Blocking Immunity, Bands 2&3 | Offset = +/- 1 MHz Offset = +/- 2 MHz Offset = +/- 10 MHz | - - - | 71 72 78 | - - - | dB dB dB |
| IIP2 | 2nd order Input Intercept Point Unwanted tones are 20 MHz above the LO | Highest LNA gain | - | +55 | - | dBm |
|---|---|---|---|---|---|---|
| IIP3_HF | 3rd order Input Intercept point Unwanted tones are 1MHz and 1.995 MHz above the LO | Band 1 Highest LNA gain G1 LNA gain G2, 5dB sensitivity hit | - - | -11 -6 | - - | dBm dBm |
| IIP3_LF | 3rd order Input Intercept point Unwanted tones are 1MHz and | Band 2 Highest LNA gain G1 LNA gain G2, 2.5dB sensitivity hit | - - | -22 -15 | - - | dBm dBm |
| 1.995 MHz above the LO | Band 3 Highest LNA gain G1 LNA gain G2, 2.5dB sensitivity hit | - - | -15 -11 | - - | dBm dBm | |
| BW_SSB | Single Side channel filter BW | Programmable | 2.7 | - | 250 | kHz |
| IMR | Image Rejection | Wanted signal 3dB over sensitivity BER=0.1% | - | 50 | - | dB |
| IMA | Image Attenuation | - | 57 | - | dB | |
| DR_RSSI | RSSI Dynamic Range | AGC enabled Min Max | - - | -127 0 | - - | dBm dBm |
* RxBw = 83 kHz (Single Side Bandwidth)
2.5.4. FSK/OOK Mode Transmitter
Table 9 Transmitter Specification
| Symbol | Description | Conditions | Min | Typ | Max | Unit |
|---|---|---|---|---|---|---|
| RF_OP | RF output power in 50 ohms on RFO pin (High efficiency PA). | Programmable with steps Max Min | - - | +14 -1 | - - | dBm dBm |
| ΔRF_ OP_V | RF output power stability on RFO pin versus voltage supply. | VDD = 2.5 V to 3.3 V VDD = 1.8 V to 3.7 V | - - | 3 8 | - - | dB dB |
| RF_OPH | RF output power in 50 ohms, on PA_BOOST pin (Regulated PA). | Programmable with 1dB steps Max Min | - - | +17 +2 | - - | dBm dBm |
| RF_OPH_ MAX | Max RF output power, on PA_BOOST pin | High power mode | - | +20 | - | dBm |
| ΔRF_ OPH_V | RF output power stability on PA BOOST pin versus voltage supply. | VDD = 2.4 V to 3.7 V | - | +/-1 | - | dB |
| ΔRF_T | RF output power stability versus temperature on PA_BOOST pin. | From T = -40 °C to +85 °C | - | +/-1 | - | dB |
** RxBw = 50 kHz (Single Side Bandwidth)
*** RxBw = 250 kHz (Single Side Bandwidth)
| 169 MHz, Band 3 10kHz Offset 50kHz Offset 400kHz Offset 1MHz Offset | - - - - | -118 -118 -128 -134 | - - - - | dBc/ Hz | ||
|---|---|---|---|---|---|---|
| PHN | Transmitter Phase Noise | 433 MHz, Band 2 10kHz Offset 50kHz Offset 400kHz Offset 1MHz Offset | - - - - | -110 -110 -122 -129 | - - - - | dBc/ Hz |
| 868/915 MHz, Band 1 10kHz Offset 50kHz Offset 400kHz Offset 1MHz Offset | - - - - | -103 -103 -115 -122 | - - - - | dBc/ Hz | ||
| ACP | Transmitter adjacent channel power (measured at 25 kHz offset) | BT=1. Measurement conditions as defined by EN 300 220-1 V2.3.1 | - | - | -37 | dBm |
| TS_TR | Transmitter wake up time, to the first rising edge of DCLK | Frequency Synthesizer enabled, PaR amp = 10us, BR = 4.8 kb/s | - | 120 | - | us |
Thermal Information
©2016 Semtech Corporation
Table 5 Thermal Properties
| Symbol | Description | Min | Typ | Max | Unit |
|---|---|---|---|---|---|
| THETA_JA | Package θja (Junction to ambient) | - | 22.185 | - | °C/W |
| THETA_JC | Package θjc (Junction to case ground paddle) | - | 0.757 | - | °C/W |
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