BQ25756: New Design using BQ25756 Battery Charger

Dante Fasano

Intellectual 300 points

Part Number: BQ25756
Other Parts Discussed in Thread: BQ25672

Hello,

I am starting a new single cell lithium battery design using the BQ25756 bidirectional charger.

The bidirectional feature is very important to this design.

I am wondering if there are any example 1-cell bidirectional designs available for me to look at?

Best,

Dan

over 1 year ago

0 Dante Fasano over 1 year ago

Intellectual 300 points

Quick follow-up.

This design must work with input voltages from 4V to 28V.

0 Charles Harthan over 1 year ago in reply to Dante Fasano

TI__Intellectual 2010 points

Hi Dante,

We do not have a 1S charger that supports up to 28V operating Vin.

For a buck charger that is close to the requirements, i would recommend BQ25672 here. This device is a 1-4S buck charger that supports up to 24V Vin. It also has OTG mode which boosts the battery voltage to the input pin.

BQ25756 is the only products in our portfolio that can support 28V Vin and have a bidirectional mode.

Regards,

Charles Harthan

0 Dante Fasano over 1 year ago in reply to Charles Harthan

Intellectual 300 points

Hi Charles,

Thank you for the response. I'm not sure I completely understand.

The datasheet for the BQ25756 says it can handle 1S to 14S for batteries and it has an input upto 70V.

So, what am I missing?

Dan

0 Ethan Galloway over 1 year ago in reply to Dante Fasano

TI__Mastermind 30915 points

Hello Dante,

Thanks for being patient with this. I am the applications engineer for the BQ25756.

Yes, the BQ25756 does support bidirectional charge and it can charge a 1S battery.

For an example of how to use and layout the BQ25756, you can look at the EVM. We don't have any examples specifically of 1S bidirectional charging though.

Let me know if you have any more questions.

Best Regards,
Ethan Galloway

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BQ25756: New Design using BQ25756 Battery Charger