BQ25890H: BQ24262 charging profile

Nam, Dino

Part Number: BQ25890H
Other Parts Discussed in Thread: BQ24262, BQ25890

Dear team,

I know BQ24262 is obsolete part and My customer already develop their product using BQ25890H instead of BQ24262 but There is some stock of BQ24262 left at customer site. They are trying to use BQ24262 for small quantity application so please review below question regarding charging profile and let me know your opinion.

Below waveform is the Charge Current waveform of BQ24262. The expected waveform is #1, but there is abnormal waveform like red period of #2 waveform.

Why is there a red period without falling right away like typical charging profile?

Thank you.

over 3 years ago

0 Wyatt Keller over 3 years ago

TI__Guru** 103375 points

Hello Dino,

Is this question regarding the BQ25890 or BQ24262?

Sincerely,

Wyatt Keller

0 Nam, Dino over 3 years ago in reply to Wyatt Keller

TI__Expert 6255 points

Hello Wyatt,

This question is for BQ24262.

I can't create new thread with BQ24262.

Please review it again and let me know your opinion regarding abnormal charge current waveform of BQ24262.

Thank you.

0 Ning T over 3 years ago in reply to Nam, Dino

TI__Guru 51451 points

Dino,

Assigning the thread to the related support.

Thanks,

Ning.

0 Jeff F over 3 years ago in reply to Ning T

TI__Guru**** 151535 points

Hi Dino,

The older chargers had a difficult time transitioning from constant current analog feedback loop to constant voltage analog feedback loop. Higher impedance between BAT pin and battery makes the transition more pronounced, like is shown above.

Regards,

Jeff

0 Nam, Dino over 3 years ago in reply to Jeff F

TI__Expert 6255 points

Hello Jeff,

Thank you for your response.

I am sorry but would you please explain why higher impedance between BAT pin and battery makes difficult time transitioning from CC to CV more detail? Is there any recommended impedance value?

Thank you.

+1 Jeff F over 3 years ago in reply to Nam, Dino

TI__Guru**** 151535 points

Hi Dino,

Higher impedance always increase taper time and so will increase the transition time from CC to CV. There is no recommended impedance. The time varies directly with impedance, i.e. lower impedance results in shorter time.

Regards,

Jeff

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BQ25890H: BQ24262 charging profile