npm1300 charge indication LED

[scjr_dev]

Hi,

I am using the nPM1300 PMIC and the LED drivers configured so that:

• Green LED = charging status (PMIC-driven)

• Red LED = error indication

Normally, when charging, the green LED is solid ON, and when there is an error the red LED turns ON, which matches the documentation.

However, I recently encountered a situation where:

• No red LED (no error indicated)

• Green LED is blinking at a constant fixed rate

• Charging cable (VBUS) is connected and battery connected (fuel gauge display a valid %)

It also seems the battery is not charging in this state. I let the unit connected few hours and % remains the same.

From the documentation I could find, the charging LED behavior seems to only specify solid ON (charging) or OFF (not charging / complete). I did not see any description of a blinking green LED state when the LED is configured for charging status and driven directly by the PMIC.

Does the nPM1300 charging status LED ever blink by design, and if so what condition does it represent?

Thanks!

[Szabolcs]

Hi Jerome!

It sounds like the device is trying to start charging periodically, but always fails to do so. I have a few questions/pointers to help you debug the problem:

1. Does the blinking stop after a while, or goes on indefinitely?
2. What hardware are you using, is it a DK/EK or a custom board?
3. Can you share some logging info (e.g. Record Events option of nPM PowerUP)?
4. What kind of battery are you using, how is its condition?
5. What is the state/%/voltage of the battery?
6. Did you try multiple batteries?
7. What is the frequency of the blinking of the LED?
8. Is the VBUS voltage stable?
9. Can you show VBUS, VBAT, and the LED voltage on an oscilloscope plot? (All the same time.)
10. What is the battery charging current?