SE868Kx-Ax Family Product User Guide
1VV0301201 Rev. 5
Page 25 of 83
2021-07-15
Not Subject to NDA
If power is removed from Vbatt, then Time, Ephemeris, Almanac, EASY, EPO data, and
PMTK configuration data will be lost. If Vbatt is maintained, no data will be lost.
4.14.2.
Backup Mode (Perpetual)
(SE868-A and SE868K3-Ax only)
In the backup mode, the internal Power Management Unit is turned off, leaving only
BBRAM and the RTC powered up. This reduces power consumption to the minimum
required that still provides data retention to enable hot and warm starts.
To enter the Perpetual Backup mode, use the NMEA command: $PMTK225,4.
Note: Only the SE868-A and SE868K3-Ax have a Force_On pin.
This command will be rejected on the other modules (SE868-AS and
SE868K7-Ax).
To exit the Perpetual Backup mode, bring the Force_On signal high, then return to low.
Please refer to Section 9.5.2.2
FORCE_ON (SE868-A and SE868K3-Ax only)
4.14.3.
Standby Modes
In these modes, the receiver stops navigation, the internal processor enters the standby
state, and the current drain at main supply VCC_IN is substantially reduced.
STOP: ARM baseband, RF, and TCXO are powered down
SLEEP: ARM baseband and RF are powered down
To enter a Standby mode, send the following command:
$PMTK161,0*28
(STOP Mode)
$PMTK161,1*29
(SLEEP Mode)
To exit a Standby mode, send any byte to the host port (RX).
4.14.4.
GLP Mode (SE868-A and SE868K3-Ax only)
In the GNSS Low Power (GLP) mode, power consumption is reduced for some time during
a one second period. The module will alternate this cycling with periods of full power
when necessary, for example weak signals or decoding the navigation message.
A typical current draw is 10 to 14 mA, depending on conditions.
Note that position accuracy will be reduced during GLP operation, therefore the user
must determine the tradeoff between power consumption and desired accuracy.
A timeline is shown below:
