BQ25882: Out of range when termination current at 50mA setting

PAN-M

Part Number: BQ25882

Hi,

It is written in the datasheet that an error when I set a termination current to 50mA is ±40%.
Therefore, the upper side is 70mA.
I measured termination current in two following environment.

1) BQ25882EVM-001 + 2cell Battery + Ammeter (BAT+ <-Meter-> Battery)

2) BQ25882EVM-001 + 2cell Battery + Voltage Meter (both end of R6(10mohm))

Even if several times of results measured termination current, it exceed 80mA.
Is this problem of device or EVM or setting?
In any event, please teach me the reason because I want to reappear.

Best Regards,
PAN-M

over 5 years ago

0 Michael Emanuel35 over 5 years ago

TI__Mastermind 40305 points

Hi PAN-M,

We have verified the termination current is within the specification under the given conditions before. The possible discrepancy could be related to the setup or measurement accuracy. For setup 1, we don’t recommend putting a meter within the loop as it changes the loop characteristic. For setup 2, minimizing the connection of the impedance and making sure the calibrated meter has the expected capability (10 µV represents 1 mA) are important.

Thanks,

Mike Emanuel

0 PAN-M over 5 years ago in reply to Michael Emanuel35

Mastermind 8375 points

Mike-san

Thank you for support.
In the case of 2, the measuring instrument is connected to resistance in parallel.
A resistance level must be high to misread a current value highly.
How should this point intend?

bq25882_E2E.pdf

Best Regards,
PAN-M

0 Michael Emanuel35 over 5 years ago in reply to PAN-M

TI__Mastermind 40305 points

Hi PAN-M,

The sense resistor is primarily for high current measurement. The sense resistor is not good for measuring termination current accuracy.

Thanks,

Mike Emanuel

0 PAN-M over 5 years ago in reply to Michael Emanuel35

Mastermind 8375 points

Mike-san

The specifications of termination current of this device are to 50mA.
When you cannot use this specification, please revise the datasheet.

Regards,
PAN-M

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BQ25882: Out of range when termination current at 50mA setting