Good evening.
We are building an embedded system with sleep capabilities and a battery to preserve datetime. But the battery current usage is too high. We use an i.MX 6ULL V1.1A, the battery is connect to pin 40 and to test we cut all other connections to SNVS (Secure Non-Volatile Storage) pins. Still the current is 21 mili ampères instead of ~35 micro ampères.
During our tests without cutting the circuit connections some times the current consumption was right, some times it was wrong. Is there a way to turn off the operating system in a way to always use only battery to supply RTC circuit?
Can you confirm that all connections to SNVS are being removed and there is no back feeding?
Below are some comments on the Colibri iMX6ULL datasheet:
These pins are in the SNVS power block of the SoC. This means the pins remain powered in the
“RTC Only” power mode by the VCC_BATT rail. Make sure there is no back feeding on this pin.
Otherwise a high RTC battery consumption can be caused. More information can be found in section 5.1 and 6.2.
Good evening.
We tested again and have absolute certain that – excluding the battery – all connections to SVNS pins were removed and after the Linux “shutdown now” command the SOM still consumes ~22mA.
When we physically remove the power without shutdown command the consumption drops to ~35uA.
Can you please share with us which BSP you are using in these tests?
I believe you also have a Viola on your side, is it possible to reproduce the issue using the Viola carrier board?
I will try to reproduce the issue here on one of our carrier boards and let you know the results as soon as possible. The idea of this test is to check if the issue is related to hardware or software.
