BQ25750EVM: BQ25750EVM - Charge current different from Datasheet

Mateus Umbelino

Part Number: BQ25750EVM
Other Parts Discussed in Thread: BQSTUDIO, BQ25750

Tool/software:

Hello!

Recently I started testing the BQ25750EVM and noticed that the current and voltage logs are not consistent with the datasheet.

Here's the log made with BQSTUDIO.

Is this the expected behaivior? What is this second current spike? Why does the graph show 2 CV voltages?

I'm attaching the raw log from BQSTUDIO.

5265.LOG1.log

4 months ago

0 Ethan Galloway 4 months ago

TI__Mastermind 19320 points

Hello Mateus,

We do not provide a specification for the BQ25750's ADC accuracy. For accurate measurements, I recommend using a voltmeter or current meter.

Also, we recommend to set EN_PFM=0 when terminating below 2A.

Best Regards,
Ethan Galloway

0 Mateus Umbelino 4 months ago in reply to Ethan Galloway

Prodigy 36 points

Hello Ethan,

I think that the problem is not the resolution of the ADC, but the absence of the "pre-charge" and the fact that the charging "restarted" a new charging cycle before ending the first one. Why is it that the cycle is so different from the one specified in the datasheet?

0 Ethan Galloway 4 months ago in reply to Mateus Umbelino

TI__Mastermind 19320 points

Hello Mateus,

I can't quite read the register file you sent. Can you make sure EN_PFM=0 when you are doing these tests?

The charger termination doesn't work well if EN_PFM=1.

Best Regards,
Ethan Galloway

0 Mateus Umbelino 4 months ago in reply to Ethan Galloway

Prodigy 36 points

Hi Ethan,

EN_PFM was enabled. I'll make another cycle with this EN_PFM=0. Thanks for the support.

0 Ethan Galloway 4 months ago in reply to Mateus Umbelino

TI__Mastermind 19320 points

Hello Mateus,

Thanks for working through this. Let me know if that resolves the issue.

Best Regards,
Ethan Galloway

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BQ25750EVM: BQ25750EVM - Charge current different from Datasheet