BQ25756E: Could u help to check whether the SW1 waveform is normal or not?

Intellectual 2370 points

Part Number: BQ25756E

Tool/software:

Hi, Team

Our customer use BQ25756E in one of the project, and they can see SW1 have some ringing and drop.

i am not sure whether this waveform is the typical DCM waveform.

Pls check the attachment for more detail.

Thanks.

G.W

BQ25756 SW waveform.pptx

11 months ago

0 Ethan Galloway 11 months ago

TI__Mastermind 32175 points

Hello GW,

Thanks for being patient with this. I'll look into this and get back to you later this week.

Best Regards,
Ethan Galloway

0 GW 11 months ago in reply to Ethan Galloway

TI__Intellectual 2370 points

Hi, Ethan

Could u help to share your comments?

Thanks.

G.W

0 Ethan Galloway 11 months ago in reply to GW

TI__Mastermind 32175 points

Hello G.W,

Thanks for being patient with this. This waveform looks normal for low current charging while in DCM mode. What's the customer's charge current here?

Best Regards,
Ethan Galloway

0 GW 11 months ago in reply to Ethan Galloway

TI__Intellectual 2370 points

Hi, Ethan

The attachment has the test condition, and i copy it as below:

Test condition:

Vin:35V

Vbat:23V

I_charger:2.4A

and the inductor is 6.8uH.

Could u help to double confirm for such test condition?

Thanks.

G.W

0 Ethan Galloway 11 months ago in reply to GW

TI__Mastermind 32175 points

Hello G.W,

I don't think the waveform looks good for a charging current of 2.4A. If the customer wants to investigate this further, can you send me the schematic and the part number of the inductor?

Best Regards,
Ethan Galloway

0 GW 11 months ago in reply to Ethan Galloway

TI__Intellectual 2370 points

Hi Ethan

As this project is a confidential for end customer, i will share the SCH and inductor P/N to you in e-mail.

Thanks.

G.W

0 Ethan Galloway 11 months ago in reply to GW

TI__Mastermind 32175 points

Hello G.W,

Thanks. I'm going to mark this thread as resolved for now and respond to you over email.

Best Regards,
Ethan Galloway

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BQ25756E: Could u help to check whether the SW1 waveform is normal or not?