User's Manual

GSM/GPRS/GNSS Module Series
MC20 Hardware Design
MC20_Hardware_Design Confidential / Released 31 / 95
3.3.3.2. Reference Design for Power Supply of GNSS Part
The power supply for GNSS part is controlled by the GSM part through AT command control over
GNSS_VCC_EN pin.
A reference circuit for the GNSS part power supply is given below. Please pay attention to the electrical
characteristics of GNSS_VCC_EN to match LDO’s EN pin. Please refer to document [1] for details about
the AT commands for GNSS control.
Figure 9: Reference Circuit Design for GNSS Part
3.3.4. Monitor Power Supply
The command AT+CBC can be used to monitor the supply voltage of the GSM part. The unit of the
displayed voltage is mV.
For details, please refer to document [1].
3.3.5. Backup Domain of GNSS
The GNSS part of MC20 module features a backup domain which contains all the necessary GNSS
information for quick start-up and a small amount of user configuration variables. In GNSS’s backup mode,
the backup domain is still alive. As long as the backup domain is alive, EASY technology will be available.
As the GNSS’s backup domain is powered by VBAT, the GNSS’s backup mode will be active as long as
the following conditions are satisfied at the same time: