Installation Instructions
Table Of Contents
- Contents
- List of Table
- List of Figures
- 1 About this document
- 2 Product Overview
- 3 Mechanical Dimensions
- 4 Interface description
- 4.1 Pin Definition
- 4.2 Operating conditions
- 4.3 Digital logic characteristics
- 4.4 Power interface
- 4.5 USIM card interface
- 4.6 PCM interface
- 4.7 USB2.0 interface
- 4.8 UART interface
- 4.9 SPI interface
- 4.10 I2C interface
- 4.11 Network light
- 4.12 System Status Indication
- 4.13 Flight Mode
- 4.14 Forced USB download interface
- 4.15 SD card interface
- 4.16 SDIO_WIFI/EMMC interface
- 4.17 PCIe interface
- 4.18 RMII/RGMII interface
- 4.19 AUDIO interface
- 4.20 ADC
- 4.21 GPIOs
- 4.22 Power on/off and reset interface
- 4.23 Antenna interface
- 5 Product characteristics
- 6 Design Guideline
- 7 Storage, Production and Package
- 8 Safety Information
- 空白页面
- 空白页面
L508 Hardware Design
Copyright© Shanghai Mobiletek Communication Ltd 90
Main antenna matching circuit
If the connection between the RF port of the module and the antenna interface is required, the
microstrip or stripline between the module RF test stand and the antenna interface RF test stand is
designed for 50 ohms of characteristic impedance in the circuit design of the motherboard, if the RF
connector of the antenna can be directly stuck on the RF test stand of the module, the connection
between the RF port of the module and the antenna interface can be omitted.
6.4 EMC AND ESD design recommendations
The user should take the EMC problem caused by the Signal integrity and power integrity into
account when designing the whole machine. When the layout of the peripheral circuit of the module is
laid out, the power and signal lines should be laid out with the width of 2 times of the spacing between
the lines, it can effectively reduce the coupling between signals, so that the signals have a "clean"
return path. When designing the peripheral power circuit, the decoupling capacitor should be placed
close to the module power pin, the high-frequency high-speed circuit and the sensitive circuit should
be far away from the PCB edge, and the layout should be isolated as far as possible to reduce the
mutual interference, the sensitive signal is protected and the shielding design is made for the circuit
or device which may interfere with the operation of the module.
This product is embedded in the side of the system board, need to pay attention to the design of ESD
protection, key input and output signal interface, such as U Sim Card Signal Interface, need to place
ESD devices nearby for protection, in addition to the side of the motherboard, the user is required to
design the structure parts and PCB layout reasonably, ensure the metal shield shell to be grounded
sufficiently, and set up a smooth discharge channel for electrostatic discharge.
6.5 Product Recommendation Upgrade Program
L508 updates firmware via USB by default, so it is recommended that USB test points or interfaces
be set aside at design time to facilitate firmware updates for subsequent products.