BQ24032A: questions on schematic

agusta mir

Part Number: BQ24032A

I added a gauge chip to my existing charger design. I asked a question here, but was asked to re-post to get someone from the charger team to look at it. I have most of the design in the charger worked out. Can someone help with the following questions:

- There is a 10uF cap(c28) across the pack terminals (from the BQ24032A design). Now that the gauge output is connected to the BAT terminal of BQ24032A chip, do I keep the cap?

- Can the CE chip on BQ24032 be pulled up with a 10k resistor or needs some other valued resistor (since PSEL has 100k pull-up). I want ACIN to be connected to out in the absence of BAT input.

- Can the LDO pin on BQ24032 be left unconnected?

over 5 years ago

0 Raheem over 5 years ago

TI__Mastermind 21590 points

Hello,
On section 11.2.2.1, it is recommended to have a minimum of 33uF capacitor between BAT and VSS.
CE can be pulled up with either 10k or 100k. Depending on your input, having a higher resistance will reduce the current.
For the LDO, it can be left unconnected if you don't intend to use it.

0 agusta mir over 5 years ago in reply to Raheem

Intellectual 480 points

Thanks for the answer. Can you please quickly clarify this: The typical application schematic has some deviations from the recommended values in section 11.2.2.1. For example application schematic has a 10uF cap on output and recommended values asks for a 0.1uF cap. Similarly the BAT-VSS cap is recommended to be atleast 33uF and the application schematic has 1uF. Can you please tell me why these deviations exist?

0 Raheem over 5 years ago in reply to agusta mir

TI__Mastermind 21590 points

Hello,
If you look at section 11.2.2, the 33uF capacitor is recommended to allow for operation when the battery is absent. If you don't require that, a 10uF capacitor should be fine.

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BQ24032A: questions on schematic