bq24610 overcurrent detect

Hirotsugu Kobayashi

Mastermind 9540 points

Other Parts Discussed in Thread: BQ24610

How does bq24610 detect an over current?

Is it a peak current of high-side SW or the average output current?

over 9 years ago

0 Steven Bangdiwala over 9 years ago

TI__Expert 8690 points

Hi Hirotsugu,

The bq24610 uses an overcurrent protection for charging. The threshold is 160% of charging current. You can read it under "Cycle-by-Cycle Charge Overcurrent Protection" on section 9.3.16 of datasheet. Also under "Charge Overcurrent Comparator (Cycle-by-Cycle)" on page 9.

Thanks,
Steven

0 Hirotsugu Kobayashi over 9 years ago in reply to Steven Bangdiwala

Mastermind 9540 points

Hi Steve,

I think a waveform of V(srp-srn) is triangular, so I want to know how detect OCP, peak voltage or averaege voltage of V(srp-srn).

And I have one more question.
What meaning is "mean the charge overcurrent threshold floor" and "charge overcurrent threshold ceiling"?

0 Steven Bangdiwala over 9 years ago in reply to Hirotsugu Kobayashi

TI__Expert 8690 points

Hirotsugu,

Peak voltage would trigger OCP.

As for the other two specs:
"Charge overcurrent threshold floor" means that 50mV will be the lowest OCP will trigger, which is in the case of 3.125A of charging current setting. 3.125 (charging current)*0.010 (sense resistor)*1.6 (160% of charging current)=50mV

"Charge overcurrent threshold ceiling" means anything above V(srp-srn)>180mV will trigger OCP no matter what % of charging current.

Thanks,
Steven

0 Hirotsugu Kobayashi over 9 years ago in reply to Steven Bangdiwala

Mastermind 9540 points

Hi Steve,

I would like to know the MIN & MAX value of OCP threshold.(typical is 160%)

Best Regards,

0 Steven Bangdiwala over 9 years ago in reply to Hirotsugu Kobayashi

TI__Expert 8690 points

Hirotsugu,

There is no MIN or MAX threshold because of the two specs I described in the previous post. Depending if programmed charge current is too high or too low, the OCP % threshold may be different due to floor and ceiling values.

Thanks,
Steven

0 Hirotsugu Kobayashi over 9 years ago in reply to Steven Bangdiwala

Mastermind 9540 points

Hi, Steve.
Our conditon is follows,
Rsns=50mOhm, VISET=1V so Icharge is 1A and Vsns is 50mV.
Under this condition, OCP detects when Icharge_peak is 1.6A.

I think OCP threshold is follows,
If too lower Vrsns is set, it isn't detecet until Vrsns will be 50mV in spite of Icharge is more than 160%.
If too higher Vrsns is set, it detect when Vrsns will be 180mV in spite of Icharge is less than 160%.
Is this understanding right?

Best Regards,

0 Steven Bangdiwala over 9 years ago in reply to Hirotsugu Kobayashi

TI__Expert 8690 points

Hirotsugu,

Yes you are correct.

Thanks,
Steven

0 Hirotsugu Kobayashi over 9 years ago in reply to Steven Bangdiwala

Mastermind 9540 points

Hi, Steve.
Thank you for your answer.
I could understand well.

But I think the tolerance of the OCP threshold when being designed by the appropriate condition, should be prescribed.
Isn't there a reference value?

Best Regards,

0 Hirotsugu Kobayashi over 9 years ago in reply to Hirotsugu Kobayashi

Mastermind 9540 points

Please let me know the min/max value of OCP threshold in synchronous mode.

0 Steven Bangdiwala over 9 years ago in reply to Hirotsugu Kobayashi

TI__Expert 8690 points

Hirotsugu,

Sorry for the delay. This parameter is characterized from 156% to 177%.

Thanks,
Steven

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bq24610 overcurrent detect