Backup Mode - Quectel L76 Hardware Design

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Sending corresponding command will make the modules enter Standby mode. Sending any data via
UART will make the modules exit standby mode as UART is still accessible in Standby mode.
When the modules exits from Standby mode, it will use all internal aiding information like GPS time,
ephemeris, last position, etc., resulting in the fastest possible TTFF in either hot or warm start. For more
information about these commands to enter or exit from Standby mode, see document [1].
NOTE
The STANDBY pin is edge-triggered, so the modules may unexpectedly enter Standby mode when it
starts. To avoid this, it is recommended to set your GPIO which controls STANDBY pin as input before
the modules start. After that, you can reset the GPIO as output to control the STANDBY pin. If it is
unused, keep it open.

3.3.3. Backup Mode

For power-sensitive applications, the module receiver provides a Backup mode to reduce power
consumption.
Backup mode requires lower power consumption than Standby mode. In this mode, the modules stop
acquiring and tracking satellites. The UART is not accessible. But the backed-up memory in RTC domain
which contains all the necessary GPS information for quick start-up and a small amount of user
configuration variables is maintained. Due to the backed-up memory, EASY™ technology is available.
If the power supply to VCC pin is cut off and V_BCKP pin is powering the RTC domain, the modules
switch from Continuous mode to Backup mode. Only RTC domain is active in Backup mode and it keeps
tracking time. As soon as the VCC pin is powered, the modules immediately switch to Continuous mode.
The following describes how to switch between Backup mode and Continuous mode.
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Keep the WAKEUP pin open or low (the signal shown as red line in Figure 3) and send software
command to enter Backup mode. The only way to wake up the modules is by pulling the WAKEUP
pin high (signal shown as a red line in Figure 3 ). For more information about the command, see
document [1].
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Cutting off the power supply to VCC pin and keeping V_BCKP pin powered will make the modules
exit from Continuous mode and enter Backup mode.
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