Semtech LR1121 - Introduction; Scope; Overview; Figure 1-1: LR1121 Block Diagram

LR1121
User Manual Rev 1.1
UM.LR1121.W.APP Mar 2023
12 of 130
Semtech
Proprietary & Confidential
www.semtech.com
1. Introduction
1.1 Scope
This document provides complete information on how to use the LR1121 transceiver in an application. It covers both
hardware and software aspects. For LR1121 functionalities and circuit specifications, refer to the LR1121 Datasheet.
Figure 1-1: LR1121 Block Diagram
1.2 Overview
The LR1121 chip is a long range, ultra-low power transceiver that provides ISM sub-GHz, a global 2.4 GHz band, and
1.9GHz-2.2GHz S-Band communication targeting terrestrial and satellite connectivity. For LPWAN use cases, the LR1121
supports LoRa® and (G)FSK and Long Range-Frequency Hopping Spread Spectrum (LR-FHSS) modulations. The device is
highly configurable over the 150 MHz-960MHz, 1.9-2.1GHz Satellite band and 2.4GHz ISM bands to meet different
application requirements utilizing the global LoRaWAN® Standard or proprietary protocols.
Besides the world-wide sub-GHz, 1.9-2.1GHz Satellite band and 2.4GHz transceiver capabilities, the LR1121 features a very
low power multi-band front-end.
LNA
LF0
PA
HP LF
PA
LP LF
RFO_HP_LF
RFO_LP_LF
RFI_P_LF0
RFI_N_LF0
PA
HF
LNA
HF
Balun
&
Match
RFIO_HF
ADCADC
PLL
VBAT_RF
VR_PA
VREG
DCC_SW
VBAT_DCC
VBAT_RF
DC-DC
LDO
BG/IREF
POR/
BRN
PDS
REGsREGs
HFXOSC
32MHz
CKS
LFXOSC
32kHz
HFRC
32MHz
LFRC
32kHz
XTA
XTB
DIO11/ 32k_P
DIO10/32k_N
VTCXO
DIO0/ BUSY
DIO1
DIO2
DIO3
DIO4
DIO9
DIO8
DIO7
DIO6
DIO5
150 - 960MHz, RX/TX
1.9 - 2.6GHz, RX/TX
REG_PA
Digital Baseband
+ DSP
CPU
RAMROM
NVM
IO Control
Digital Front-End
LoRa
modem
(G)FSK
modem
LoRa
modem
(G)FSK
modem
nRESET