BQ24650: Heating Issue

Gururaja K

Part Number: BQ24650

Hi,

We are using BQ24650 MPPT Charge controller in solar street light project. Till 1.6A charging current there was no heating problem. When charging current is set at 5A (by changing sense resistor, inductor and capacitor values).All functional features are working fine. But Charge controller chip and PCB is getting heated up. We have provided sufficient grounding as per BQ24650 application note.

We have provided charge controller under neath via's as per the recommendations and also provided heat sink in bottom side of the PCB (4 Layer PCB).

Charging voltage is from solar panel (12V panel), MPPT value is set at 17.5V

But heating issue is not solved

Please suggest us how to solve heating issue

over 5 years ago

0 Kedar Manishankar over 5 years ago

TI__Mastermind 24075 points

Hi Gururaja,

Your solar panel OCV is 12V? If so then your MPPSET setting should be lower than this, otherwise you are always operating with BQ24650 in voltage regulation loop. MPPSET is the input voltage at which BQ24650 regulates input voltage, so solar panel can operate at its maximum power point. What FETs are you using for your switching FETs? (FET connected to HIDRV and LODRV)

0 Gururaja K over 5 years ago

Prodigy 150 points

Hi,

12V solar panel OCV is 21V and MPPT set at 17.5V. As i mentioned earlier. charging is working properly. We have noticed only heating issue.

0 Kedar Manishankar over 5 years ago in reply to Gururaja K

TI__Mastermind 24075 points

Hi Gururaja,

What switching MOSFETs are you using? Gate driver loss can be a contributor to heating.

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BQ24650: Heating Issue