L96 FORCE_ON behavour to wake up from Perpeture Backup Mode

IoT Modules GNSS Module
1

Hello!

V_BCKP and VCC directly connected to a battery. To get L96 be on Perpetual Backup Mode I set FORCE_ON to low level and then send $PMTK 224 (Perpetual Backup Mode).
It works.
Should I hold FORCE_ON always pullup to VCC to stay L96 on full on mode all time or I can use a positive impulse (low → VCC → low) ?

The docs say only about keeping FORCE_ON float or low level BEFORE backup mode, but nothing say in what state FORCE_ON should be during full on mode.

UPD: I have tested with positive FORCE_ON impulse to wake up L96 from Perpetual Backup Mode. Result: 600 mc is a minimal hold time for FORCE_ON on VCC to get L96 be woken up.

Is it documented feature?

Please, answer me.

2

Hi Ildar_Belkin,

The illustrations of Hardware Design are not explicit enough. It is recommended that to pull up FORCE_ON pin high level voltage at least 100 ms in order to wake up from backup mode. And then release the pin or drive it to low level voltage in order to prepare for the next sleep.

Best regards.

3

Hello Raphael-Q.

Thank you for answer.
I have tested 100 mc pullup to Vcc for wake up the module. 100 mc is not enought. Minimum is 600 mc.