Smart Machine Smart Decision
SIM868_Series_Hardware_Design_V1.06
48
2017-07-13
Rechargeable battery backup
Module
Power Supply
LDO/DCDC
LDO
GNSS Part
Backup
Domain
GPS_VBAT
Rechargeable
Backup Battery
VRTC
Figure 41: RTC supply from rechargeable battery
External Power
Module
Power Supply
LDO/DCDC
LDO
GNSS Part
Backup
Domain
GPS_VBAT
VRTC
2.3-4.3V
External power
Figure 42: RTC supply from external power
6.4.
Power on/off GNSS
The GNSS is controlled by GNSS_EN pin. The GNSS_EN should be pulled up to high (1.5-4.4V) through a 10k
resistor to power on the GNSS, and be pulled to low (0-0.3V) to power off GNSS.
10K
Turn on/off
impulse
LDO
Module
GNSS_EN
GPS_VBAT
2.9-4.4V
GPS
V_GPS
SIMCOM
CONFIDENTIAL
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