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 37
VBAT_BB, VBAT_RF drive baseband and RF PA chip respectively, in order to ensure VBAT_BB,
VBAT_RF voltage does not drop below 2.7V, near module, suggested to parallel a 100 uf tantalum
capacitance, low ESR and 100nF, 33nF and 10nF filter capacitance, and suggested PCB go line
short and wide enough, as far as possible in order to reduce the equivalent impedance of VBAT go
line, to ensure maximum transmitted power, voltage is no voltage drop. It is recommended that
VBAT_BB PCB trace width should not be less than 2mm and VBAT_RF PCB trace width should not
be less than 1.5mm. And the longer the line, the wider the line width, the power supply part of the
ground plane as complete as possible.
In order to suppress the power fluctuation impact and ensure the stability of the output power supply,
it is recommended to add a TVS tube with rated power above 0.5W at the front end of the power
supply and place it near the VBAT end of the module to play the role of surge protection. The
reference circuit is as follows:
VBAT_RF
VBAT_BB
GND
ZENER
100uF
100nF
33pF 10pF
VBAT
+
5.1V
ZENER
100uF
100nF
33pF 10pF
5.1V
MODULE
Figure 8 Power interface recommendation circuit
Table 14 Power Zener diode recommended
NO. Manufacturer Part Number Power Package