Telit Wireless Solutions NL865H2 Series, Руководство по конструкции аппаратуры

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NL865H2 Hardware Design Guide
1VV0301616 Rev. 7 Page 6 of 67 2020-04-20
Operating Modes ........................................................................ 21
Power Consumption ................................................................... 22
General Design Rules ................................................................. 23
4.4.1. Electrical Design Guidelines ....................................................... 23
4.4.1.1. +5V/+12V Source Power Supply Design Guidelines ................... 23
4.4.1.2. Battery Source Power Supply Design Guidelines ........................ 24
4.4.2. Thermal Design Guidelines ......................................................... 25
4.4.3. Power Supply PCB layout Guidelines ......................................... 26
RTC Bypass out .......................................................................... 26
VAUX Power Output ................................................................... 27
5. DIGITAL SECTION .................................................................... 28
Logic Levels ................................................................................ 28
Power On.................................................................................... 29
Unconditional Restart.................................................................. 29
5.3.1. PIN DESCRIPTION .................................................................... 29
5.3.2. Operating levels .......................................................................... 30
WAKEUP from PSM ................................................................... 32
5.1.1. Pin Description ........................................................................... 32
5.1.2. Application Example ................................................................... 32
Communication ports .................................................................. 35
5.2.1.1. Modem serial port 1 .................................................................... 35
5.2.1.2. Modem serial port 2 .................................................................... 36
5.2.1.3. RS232 LEVEL TRANSLATION ................................................... 37
5.2.2. 3.3V/5V UART level translation ................................................... 39
General purpose I/O ................................................................... 40
5.3.1. Using a GPIO as INPUT ............................................................. 41
5.3.2. Using a GPIO as OUTPUT ......................................................... 41
5.3.3. Indication of network service availability ..................................... 42
External SIM Holder .................................................................... 43
ADC Converter ........................................................................... 43
6. RF SECTION .............................................................................. 44
Antenna requirements................................................................. 44
6.1.1. Main Antenna ............................................................................. 44
6.1.2. PCB Design guidelines ............................................................... 45
6.1.2.1. Transmission line design ............................................................ 46
6.1.2.2. Transmission Line Measurements .............................................. 47
6.1.2.3. Antenna Installation Guidelines ................................................... 48