BQ27510-G3: Current detect accuracy of gauge

Penn Zhang

Intellectual 1180 points

Part Number: BQ27510-G3

Hi Sir,

Here is a question about the current detect accuracy.

Background: BQ27510-G3, current sense resistor = 0.01 ohm.

Can gauge detect the current that passes through the sense resistor like 0.2mA?

I think this current detect accuracy is related to ADC (coulomb counter) characteristics, so I find the INL of this ADC from the datasheet as below. then I calculated the detect current accuracy, the typical is 0.175mA, the max is 0.85mA. Is this method right form your opinion? Do you have some information of the minimum current that this gauge can detect?

And the deadband also affect the current detect accuracy, so if the deadband is 68, how about the minimum current that this gauge can detect?

Thank you.

Penn

over 6 years ago

0 Onyx Ahiakwo over 6 years ago

TI__Guru* 76230 points

hi Penn,

CC deadband will play a more crucial role in the math on what the gauge will discard. From my calculations a cc deadband of 68 will discard currents lower than 0.85mA. I am verifying this number is correct from our firmware engineer and will send a confirmation once i get verification.

thanks
Onyx

0 Penn Zhang over 6 years ago in reply to Onyx Ahiakwo

TI__Intellectual 1180 points

Hi Onyx,

Thanks for your reply.
Hope to hear the news after you get the verification.

Thank you.
Penn

0 Onyx Ahiakwo over 6 years ago in reply to Penn Zhang

TI__Guru* 76230 points

Hello Penn
Firmware engineer said 17 for cc deadband corresponds to 1mA that will be discarded. 34 will be 2mA. That is different from what i thought. I am running an overnight bench test to verify this.
thanks
Onyx

0 Penn Zhang over 6 years ago in reply to Onyx Ahiakwo

TI__Intellectual 1180 points

Hi Onyx,

I get it.

Many thanks for your work, your new test results are welcome.

Thanks

Penn

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BQ27510-G3: Current detect accuracy of gauge