BQ24725A: Removing Input/Adapter Monitoring

David P

Part Number: BQ24725A

I am trying to use the BQ24725A in a lower-cost and more simplified charger design. I have used it previously in an application where it also powered the system and utilized the input power monitoring features. My question is can I remove the input MOSFETs and sense resistor from the design and have it still function as a pure battery charger?

Thanks,

David

over 8 years ago

0 Wang5577 over 8 years ago

TI__Guru 56650 points

Yes. It can be a pure battery charger without input FETs and short out the input sense resistor. But, the charge lost the switching FET short protection.

0 David P over 8 years ago in reply to Wang5577

Intellectual 260 points

Thank you for replying to my request. Could you help and explain how I would go about doing that? I have tested my prototype by removing those FETs and the battery charging portion no longer works. Do I have to tie unused pins in any specific direction or do I leave them all floating? I appreciate your quick response.

0 Wang5577 over 8 years ago in reply to David P

TI__Guru 56650 points

If you don't need input FETs and input current sensing, please tie CMSRC, ACP and ACN together to VCC or input source "+" bus.

0 David P over 8 years ago in reply to Wang5577

Intellectual 260 points

I performed this in hardware and the charging function no longer works. Is there anything else that needs to be done in hardware or software to get this to work?

0 Wang5577 over 8 years ago in reply to David P

TI__Guru 56650 points

Please send me your schematic to me or post it in here. wang-li@ti.com

Also, "not work" doesn't provide enough info. What is the ACDET voltage? ACOK is high or low? Does "not work" mean the charger cannot enable charge? Or do you mean some functions cannot work?

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BQ24725A: Removing Input/Adapter Monitoring