GT-1612-MTBD
GPS&Beidou Receiver Module
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Page 9 of 35
Revision: V2.0.1-January 2015
If your power supply circuit adopts the design mentioned above , GT-1612-MTBD module does not support
EASY technology and backup mode as well as other modes related to it,e.g. AlwaysLocate
™
backup mode.
The other way is feeding VBAT through a backup battery directly. The module will enter into backup mode when
power source (3.3V) is cut off. Furthermore,it is necessary to add an external charging circuit.for rechargeable battery.
The detailed schematic (mount R2 with 0R to replace Power switch) is shown as there is no charge source when
power source (3.3V) is cut off. MS621FE FL11E from Seiko is recommended. The consumption of VBAT is as low as
20uA in backup mode.
The schematic with power supply circuit is shown as below. As power source (3.3V) is always valid and the
battery is charged continuously, the capacity of the battery can be small. The detailed schematic for power switch
circuit is shown in
Figure 5.
For more details about backup mode, periodic backup mode and AlwaysLocate
™
backup mode, please refer to the
related chapters.
Figure 5:
Reference Charging Circuit for Chargeable Battery
VCC does not supply power for RTC domain in GT-1612-MTBD module, so the VBAT pin must be powered
externally. Furthermore, it is strongly recommended to supply power to VBAT through a backup battery, which can
ensure GT-1612-MTBD module supports EASY technology and improves TTFF after next restart. For details about
TTFF, please refer to
chapter 1.2.
