Real Time Clock Current Load

Autonomous Machines Jetson & Embedded Systems Jetson Nano
1

What is that current load of the Real Time clock circuit PMIC_BATT at following conditions:

1 Power ON
2 Power OFF

Second Question - If Non Rechargeable Lithium coin cell Battery is connected t the PMIC_BATT pin is there any safety concerns ?

3

The typical current of RTC part is 2uA.

Only the following types are suggested:

• super capacitor
• standard capacitors (tantalum . . . etc.)
• rechargeable lithium manganese cells

4

HI

Thanks for the answer so it is 2uA for either ON or OFF conditions correct?

What happens if by mistake a Non Rechargeable Battery was inserted instead? Is there any damage to the Jetson Nano charging circuit? Are there any other risk issues that may happen?

Regards
Mati

5

It’s 2uA. Not suggest to use others than mentioned three.

6

Thanks for clarifying.

Other questions . Can you describe the Charging circuit operation?

  1. How are the CV and CC levels programmed?
  2. How is the charging cycle implemented ? (The ML1220 number of charging cycle is 1000 for normal cycle)
  3. We plan to use the ML1220 do you have any programming suggestions for the CC and CV for this battery to make it the longer life time possible ?
    Regards

Mati

9

Look for backup-battery node in device tree
it has CC and CV default value.
there are many threads on the values in devtalk