Telit Wireless Solutions LN920, Hw Design Manual

Page: 4 / 81

LN920 HW Design Guide
1VV0301730 Rev. 1
Page 4 of 81 2021-08-11
Not Subject to NDA
4. POWER SUPPLY 28
Power Supply Requirements 28
Power Consumption 28
4.2.1. Idle Mode 29
4.2.2. LN920 Connected Mode Current Consumption 29
General Design Rules 30
4.3.1. Electrical Design Guidelines 30
4.3.1.1. +5V Source Power Supply Design Guidelines 30
4.3.2. Thermal Design Guidelines 31
4.3.3. Power Supply PCB Layout Guidelines 32
RTC (Real Time Clock) 33
5. ELECTRICAL SPECIFICATIONS 34
Absolute Maximum Ratings – Not Optional 34
Recommended Operating Conditions 34
6. DIGITAL SECTION 35
Logic Levels 36
Power On 37
6.2.1. Initialization and Activation State 37
Power Off 38
6.3.1. Graceful Shutdown 39
6.3.2. Fast Shutdown 39
RESET 41
6.4.1. Unconditional Hardware Reset 41
Communication Ports 42
6.5.1. USB Interface 42
6.5.2. SIM Interface 44
6.5.2.1. SIM Schematic Example 45
6.5.3. Control Signals 45
6.5.4. General Purpose I/O 46
6.5.4.1. Using a GPIO as INPUT 47
6.5.4.2. Using a GPIO as OUTPUT 47
I2C – Inter-integrated circuit 48