QB20SeriesLoRaModule
-Cost-effective-Small-size-SPI-Interface

QB20 Series LoRa Module

QB20 Serial LoRa SIP Module integrates SX1262 RF transceiver and RF front-end circuit inside. Only an external 32MHz TCXO or passive crystal is required when using it. This module supports LoRa and FSK modulation. The maximum transmit power of the module is up to +22dBm, and the receiving sensitivity can reach -148 dBm. Its unique modulation method makes its anti-interference ability strong. The module package is LGA24, and the size is 8.0mm x 8.0mm x 2.0mm.

Features

• Working Band
  – 470~510MHz(L-LRMQB20-77NN4)
  – 860~930MHz(L-LRMQB20-97NN4)
• Ultra small size
  – 8.0mm*8.0mm*2.0mm
• Multiple modulation methods
  – LoRa, GFSK, FSK
• Ultra low power consumption
  – Supply Voltage 1.8V to 3.7V. (When the transmit power is +22dBm, the voltage cannot be lower than 3.1V)
  – Emission current ≤135mA (max +22dBm)
  – Receiving current ≤ 6mA (DC-DC mode, internal current)
  – 600uA standby current
  – 600nA sleep current
• High link budget
  – Sensitivity -148±1dBm (SF=12,BW_L=10.4KHz)
  – Transmit power Max. +22 dBm
• Ultra small size
  – 8.0mm*8.0mm*2.0mm
• Ultra long transmission range
  – 6Km(@SF=12,BW=125KHz, urban environment, LoRa modulation, Max.22dBm transmit)
• High privacy
  – Using a unique LoRa modulation method, the signal is difficult to capture and analyze.
• Communication Interface
  – SPI interface，easy to connect

Applications

• Smart home
• Security Monitoring
• Low-power sensors
• Remote control
• Logistics and warehousing
• Industrial control
• Long-Range transmission

Foreword
Lierda Technology Group Co., Ltd. provides the content of this document to support the product design of its customers. Customers must design their products in accordance with the specifications and parameters provided in the document. The company does not assume any responsibility for personal injury or property damage caused by improper operation of the customer. Before making a statement, Lierda has the right to update the document.
Copyright statement
The copyright of this document belongs to Lierda Co., Ltd. Anyone who reproduces or reprints this document without the permission of our company shall bear legal responsibility.
Copyright © Lierda Science & Technology Group Co.,Ltd

Document Revision History

Specifications

Table 1-1 Limit Characteristics

Table 1-2 Working Characteristics1

1. The test conditions are: temperature: 25℃, center frequency: 490MHz, working voltage: 3.3V.
2. Please configure according to the operating frequency band permitted by local regulations. Please be sure to comply with local regulations for use. If it is used in a frequency band that is not permitted by regulations, our company will not bear any
   responsibility.
3. The output power must be set according to the optimization recommendation. If the setting does not match the recommended value, the power and power consumption may not be optimal, and the module may even be damaged. The configuration is shown in Table 2-2.
4. The output power must be set according to the optimization recommendation. If the setting does not match the recommended value, the power and power consumption may not be optimal, and the module may even be damaged. The configuration is shown in Table 2-3.

Tx Power Configuration

It is necessary to configure the transmit power strictly in accordance with the table, otherwise the product may suffer from poor power consumption, performance degradation or even damage.
The power configuration registers are shown in Table 2-1. When using, you can change the SetTxParams parameter value to change the actual output power. The setting range of SetTxParams is -3~22. When configured to 22, the actual output power can reach maximum+22dBm. Note that the values of the four registers PaDutyCycle, HpMax, DeviceSel, PaLut cannot be changed, otherwise performance degradation or even module damage may occur.
Table 2-1 PA operation mode setting 

Reference codes are as follows:5 The maximum rate is proportional to the radio frequency; for example, the 868/915MHz frequency band is 300kbps, and the 433MHz frequency band is 150kbps;
6 Change the actual output power by changing SetTxParams, the maximum is 22; note that the four register values of PaDutyCycle, HpMax, DeviceSel, PaLut cannot be changed, otherwise performance degradation or module damage will occur;

Module Dimensions

3.1 Dimensions3.2 Pin Definition
Table 3-1 Pin definition

Usage

4.1 Reference Design
4.1.1 External 32MHz passive crystal

Table 4-1 Reference BOM
4.1.2 External 32MHz TCXO

Table 4-2 Reference BOM
4.1.2 Layout Attentions

• Try to connect the DIO port to the MCU IO port with external interrupt.
• The traces between the RF output of the module and the antenna pad should be as short as possible.
  A 50Ω impedance line should be used, and the ground should be covered. More holes should be punched around the trace.
• If allowed, add a π circuit from the RF output of the module to the antenna pad.
• Clearance is required around the antenna, leaving at least a 5mm clearance area.
• Pay attention to grounding, it is best to ensure a large area of ground.
• Keep the module away from high-voltage circuits and high-frequency switching circuits.
• Refer to the application document “RF PCB LAYOUT Design Rules (Applicable to Sub-1GHZ and Bluetooth Module)” for layout and wiring;。

4.2 Software operation
This module is an SPI slave device, and it can communicate with it using the SPI interface of the MCU, and operate its registers and receiving and sending buffers through API commands to complete the wireless data receiving and sending function. For the SPI operation function, the user needs to modify it according to the way his MCU operates the SPI. Please refer to the latest SX1262 data manual for the read and write operation timing of the module register;
Before software development, users can refer to the demo LoRa communication routines provided by our company and the LoRa point-to-point communication in the sample code instruction manual. When porting the code, users mainly need to adjust the SPI according to their own MCU, and then refer to the communication routines.
The point-to-point communication process using a pair of LoRa modules is shown in Figure 4-3. In this communication process example, the transmitter can send data to the receiver through LoRa, and the receiver will return the data packet through LoRa after receiving the data packet. The transmitting end. Communicate cyclically.

Prohibited Frequency

Prohibited Frequencies are the frequencies where the module performs extremely poor, and it is strictly forbidden to use it. The non-recommended frequencies are the frequencies where the module performs poor, and the customer can use it as appropriate.
It is recommended that the frequency used in the application is at least 1MHz away from the forbidden frequencies.
Prohibited Frequencies: 446MHz, 448MHz, 464MHz, 480MHz, 496MHz.
Non-recommended frequencies: 440MHz, 452MHz, 456MHz, 494MHz.

FAQ

Production Guidance

7.1 Stencil Design
The thickness of the stencil should be selected according to the package type of the device in the board, and the following requirements should be paid attention to:
The module pad position can be locally thickened to 0.15~0.20mm to avoid empty soldering;
7.2 Reflow Profile
Note: This work instruction is only suitable for lead-free work and is for reference

Ordering And Packaging

8.1 Part Number table
The Part number of QB20 series module is shown in the following table: