bq24650 / add the capacitor to between L and Rsr, meaning of I charge

Ryuji

Guru 20090 points

Other Parts Discussed in Thread: BQ24650

Hello,

Could you please kindly let me know about bq24650.

Please see the attached file.

5531.bq24650 quations.pdf

1. Our customer would like to add the capacitor to between Rsr and Inductor.(please see the page1 of attached)

Can we add the capacitor to front of Rsr ( inductor side) ?

If we can are there any restriction ?

We would like to change the current Rsr from saw tooth wave to DC current.

2.In the datasheet page 13, there is battery current regulation equation.

Is this current Peak current ? Or average current ?

Best Regards,

Ryuji Asaka

over 11 years ago

0 Charles Mauney over 11 years ago

TI__Mastermind 31120 points

I believe the filter was done the way it is, is because it helps with the lead inductance of the battery. The internal compensation is setup for this filter. Adding an extra cap would add another pole and not sure how this would effect the internal compensation. It may work, but you need to verify your design change.

0 Ryuji over 11 years ago in reply to Charles Mauney

Guru 20090 points

Hello Charles san,

Thank you for the reply.

I understood that we can use adding an extra cap for the filter of the inductor current.

But there is problem of the stability.

By the way, could I have the reply for Q2?

Icharge mean peak current of inductor for switching reg ?

Best Regards,

Ryuji Asaka

0 Charles Mauney over 11 years ago in reply to Ryuji

TI__Mastermind 31120 points

It is an average current regulation.

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bq24650 / add the capacitor to between L and Rsr, meaning of I charge