SX1301
WIRELESS & SENSING PRODUCTS Datasheet
V2.3 May 2017 www.semtech.com 2
Contents
1 PIN CONFIGURATION .................................................................................................................. 4
1.1 Pins placement and circuit marking ............................................................................................ 4
1.2 Pins description ........................................................................................................................... 5
2 ELECTRICAL CHARACTERISTICS ................................................................................................... 7
2.1 Absolute maximum ratings ......................................................................................................... 7
2.2 Constraints on external ............................................................................................................... 7
2.3 Operating conditions .................................................................................................................. 7
2.4 Electrical specifications ............................................................................................................... 8
2.5 Timing specifications ................................................................................................................... 8
3 CIRCUIT OPERATION ................................................................................................................... 9
3.1 General Presentation .................................................................................................................. 9
3.2 Power-on ..................................................................................................................................... 9
3.2.1 Power-up sequence ................................................................................................................ 9
3.2.2 Setting the circuit is low-power mode .................................................................................... 9
3.3 Clocking ..................................................................................................................................... 10
3.4 SPI Interface .............................................................................................................................. 11
3.5 Rx I/Q Interface ......................................................................................................................... 12
3.5.1 I/Q generated on clock rising edge ....................................................................................... 12
3.5.2 I/Q generated on clock falling edge ...................................................................................... 12
3.6 RX mode block diagram, reception paths characteristics ......................................................... 13
3.6.1 Block diagram ........................................................................................................................ 13
3.6.2 Reception paths characteristics ............................................................................................ 13
3.7 Packet engine and data buffers ................................................................................................ 15
3.7.1 Receiver Packet engine ......................................................................................................... 15
3.7.2 Transmitter packet engine .................................................................................................... 17
3.8 Receiver IF frequencies configuration ...................................................................................... 19
3.8.1 Configuration using 2 x SX1257 radios .................................................................................. 19
3.8.2 Two SX1255 : 433 MHz band ................................................................................................ 21
3.8.3 One SX1257 and one SX1255 ................................................................................................ 21
3.9 Connection to RF front-end ...................................................................................................... 22
3.9.1 Connection to Semtech SX1255 or SX1257 components ..................................................... 22
3.9.2 SX1301 RX operation using a third party RF front-end ......................................................... 22
3.9.3 Radio calibration ................................................................................................................... 24
3.9.4 SX1301 connection to RF front-end for TX operation ........................................................... 24
3.10 Reference application ............................................................................................................... 26
3.11 SX1301 sensitivity performance in reference application ........................................................ 27
3.12 SX1301 sensitivity vs data rate in LoRa mode........................................................................... 28
3.12.1 125kHz mode: IF8, IF[0 to 7] paths ....................................................................................... 28
3.12.2 250 & 500 kHz mode: IF8 only .............................................................................................. 29
3.13 SX1301 interference rejection .................................................................................................. 29
3.14 Hardware Abstraction Layer (HAL) ........................................................................................... 31
3.14.1 Introduction .......................................................................................................................... 31
3.14.2 Abstraction presented to the gateway host ......................................................................... 32
4 EXTERNAL COMPONENTS ......................................................................................................... 33
5 PCB LAYOUT CONSIDERATIONS ................................................................................................ 34
