BQ24780S: Charging current/voltage settings are reset when battery shorted w/ no load

Hi Tiger,

Thanks for your quick reply.

Would it be possible to explain why this phenomena occurred more detailed?

Which safety feature did reset charge current/voltage setting?

Best regards,

Shota Mago

Hi Tiger,

I got more detailed test condition information from the customer.

He shorted positive node of battery in Figure16 to GND with following condition(But battery is not connected, just open).

Then, registers of ChargeCurrent() and ChargeVoltage() were set to 0mA/0mV respectively.

• No load(output is just open, nothing was connected, no battery)
• Valid AC adaptor is attached.
• BATPRESS is pulled L externally
• REG0x12[0]=0

Do you have any idea why registers of ChargeCurrent() and ChargeVoltage() were set to 0 when charging port was shorted?

Best regards,

Shota Mago

Hi team,

Could someone reply on previous question(Do you have any idea why registers of ChargeCurrent() and ChargeVoltage() were set to 0 when charging port was shorted?)?

Best regards,

Shota Mago

Hi, Shota,

I could not confirm the customer observation in the listed conditions. Could you share the customer's schematic?

Hi Tiger,

My apologies for delayed reply.

You can access customer's schematic from this internal link.

Best regards,

Shota Mago

Thanks for the schematic. I would also need the register dump before and after the battery short event. 

Hi Tiger,

Happy new year!

I'm sorry for delayed response.

I got original(before shorting TL0715 and GND w/o any load) register dump as uploaded this TI internal folder.

As the customer doesn't have register dump after battery short event, I provide some registers which were changed after the event.

• ChargeCurrent() → 0mA
• ChargeVoltage() → 0mV
• PROCHOT Pulse Clear → Idle
• Power boost mode → Disable

Best regards,

Shota Mago

Hi, Shota,

I loaded your register settings in the EVM and repeated the same short-circuit test. The charge current and charge voltage did not change, it reversed back to normal operation after short is released. 

I could not confirm the customer observation in the listed conditions. 

Hi Tiger,

Thank you so much for confirming by EVM and I noted that the issue was not reproduced.

Best regards,

Shota Mago