User's Guide

xE922-3GR Hardware User Guide
1VV0301272 Rev.0.8 2017-01-05
Reproduction forbidden without written authorization from Telit Communications S.p.A. - All Rights
Reserved. Page 6 of 112
4.2. Recommended operating conditions .................................. 39
4.3. Logic Level Specifications ........................................ 39
5. Power supply .................................................... 41
5.1. Input supply .................................................. 41
5.2. Output supply ................................................. 42
5.2.1. Linear voltage regulators .................................. 42
5.2.1.1. VAUX_1P8V ............................................... 42
5.2.1.2. VAUX_2P85V .............................................. 43
5.2.1.3. VAUX_3P0V ............................................... 43
5.2.1.4. VSIM1/2 ................................................. 44
5.2.2. DC/DC stepdown ................................................. 44
5.2.2.1. 1V8_OUT ................................................. 44
5.3. Typical system power consumption ................................... 45
5.4. RTC backup .................................................. 47
6. Power ON/OFF and reset control ...................................... 49
6.1. Power On .................................................... 49
6.1.1. ON_OFF key action ............................................... 49
6.1.2. Switching ON due to charging ........................................ 50
6.1.3. Switching on due to RTC alarm ....................................... 50
6.2. Power off .................................................... 50
6.2.1. Soft power off ................................................... 50
6.2.2. Emergency power off .............................................. 50
6.3. Reset ....................................................... 50
7. Battery management .............................................. 51
7.1. Coulomb counter ............................................... 51
7.2. Battery charging ............................................... 52
7.2.1. Block diagram ................................................... 52
7.2.2. Battery/charger-less operation ........................................ 54
8. USIM interface .................................................. 55
9. USB port ....................................................... 57
10. Display interface ................................................ 60
10.1. MIPI-DSI .................................................. 60