[TX2] RTC function is not working properly


In my design the VDD_RTC (A50 pin) is supplied by the main battery (3.3Vdc) of the base board. When the the LAN is connected and the system is powered-off and powered-on, the date and time is updated. When the LAN is not connected the date and time is not updated when powering-off and powering-on the board.
Does I need to enable the RTC circuit of the TX2 module mannualy or it should work by default, just supplying the VDD_RTC?

Thanks in advance,

Do you mean the time will lost if power off?

Yes, the time is lost. When power on the time is not updated. It should be updated, isn’t it?

Did this happen on same module + carrier board of dev kit? If not, what’s voltage level of the pin A50 when power off?

I did not test it in the dev kit. I do not have any dev kit available right now. When in power off, the voltage level of the pin A50 is 3.3Vdc.

Is the battery chargeable? If not, can you try a super capacitor or a chargeable battery on it? Basically RTC should be enabled default.

The battery is chargeable, but the TX2 is not the charger. It always have 3.3V in the A50 pin, even if the system is on. I should use a diode to prevent the input/output issue but I did not install it yet.

“the TX2 is not the charger”? Can you the same setting of dev kit, using a super cap or coin cell on the pin to check if time can be kept?

There is no update from you for a period, assuming this is not an issue any more.
Hence we are closing this topic. If need further support, please open a new one.

Hi bernardo,

Any update? Is this still an issue to support?