User's Manual

LE920A4 HW User Guide
Doc#: 1VV0301261
Rev. 4.3 Page 7 of 123 2017-12-07
Serial Ports ....................................................................................................72
8.4.1. Modem Serial Port 1 ......................................................................................72
8.4.2. Modem Serial Port 2 ......................................................................................74
8.4.3. RS232 Level Translation ................................................................................75
Peripheral Ports .............................................................................................77
8.5.1. SPI – Serial Peripheral Interface ....................................................................77
8.5.2. I2C - Inter-integrated Circuit ...........................................................................78
8.5.3. SD/MMC Card Interface .................................................................................78
8.5.4. WiFi (SDIO) Control Interface ........................................................................80
Audio Interface ..............................................................................................81
8.6.1. Analog Audio .................................................................................................81
8.6.2. Analog Audio Characteristics .........................................................................82
8.6.2.1. Analog Inputs Characteristics ........................................................................82
8.6.2.2. Analog Output Characteristics .......................................................................84
8.6.3. Digital Audio ..................................................................................................85
8.6.3.1. Short Frame Timing Diagrams .......................................................................86
8.6.3.2. Long Frame Timing Diagrams ........................................................................88
General Purpose I/O ......................................................................................90
8.7.1. Using a GPIO Pad as Input ............................................................................91
8.7.2. Using a GPIO Pad as an Interrupt Source .....................................................92
8.7.3. Using a GPIO Pad as Output .........................................................................92
9. MISCELLANEOUS FUNCTIONS .................................................................. 93
Indication of Network Service Availability .......................................................93
RTC – Real Time Clock .................................................................................93
VAUX Power Output ......................................................................................93
ADC Converter ..............................................................................................95
9.4.1. Description .....................................................................................................95
9.4.2. Using ADC Converter ....................................................................................95
Using the Temperature Monitor Function .......................................................95
Fuel Gauge (optional) ....................................................................................95
GNSS Characteristics ....................................................................................97
10. MOUNTING THE MODULE ON YOUR BOARD ........................................... 98
General ..........................................................................................................98
Finishing & Dimensions .................................................................................98
Recommended Foot Print for the Application .................................................99
Stencil ............................................................................................................99
PCB Pad Design .......................................................................................... 100
Recommendations for PCB Pad Dimensions (mm) ...................................... 100