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 72
4.22.2 Power-on sequence
VBAT power, VAON (RTC clock source), PWRKEY also synchronous power. After the PWRKEY pin
is lowered, the module starts up, and all internal power sources such as VDD1V8 start up one after
another. When the Status pin becomes high, it means the module starts up and can be used normally.
Table 38 power-on sequencing
Symbols Pin Name Min Typ Max Unit
Ton Start-up low level pulse width 0.5 16 s
TSTATUS
BOOT time (based on the
Status Pin)
12 13 -- s
TUART
BOOT time (according to UART
judgement)
11 12 -- s
VIH
PWRKEY pin input high level
voltage
0.7*VBAT -- VBAT V
VIL
PWRKEY pin input low level
voltage
0 -- 0.3*VBAT V
The boot sequence is shown below
VBAT
PWRKEY
VDD1V8
UA RT
Ton
17ms
T
UART
不可用 可用
VAON
STATUS
T
ST AT US