BQ25856EVM: question about auto-reverse mode

TIanyi Ji

Part Number: BQ25856EVM
Other Parts Discussed in Thread: BQSTUDIO

In my test, the EN_REV bit will not enabled when the adapter is connected to the system. However, if the BQ25856EVM is already at reverse-mode without any adapter, the reverse mode will not be disabled automatically when adapter is connected. Meanwhile, the charging is stopped.

Does the reverse mode still work when the reverse-mode is on and the adapter is connected? For example, if I set the reverse voltage to 12V, and the adapter voltage is 24V, will it be a problem when the adapter is connected to VAC and the reverse mode is on?

13 天前

0 Taylor 13 天前

TI__Mastermind 36315 points

Hi,

We have received your post and the investigation will take some time. Thank you for your patience.

0 Taylor 12 天前回复 Taylor

TI__Mastermind 36315 points

Hi,

The device cannot set EN_REV when there is a power good status. If you set the reverse voltage to 12V and EN_REV, the reverse voltage register will remain 12V until it is reset, but the device will not enter reverse mode.

0 TIanyi Ji 12 天前回复 Taylor

Prodigy 30 points

Thank you for your reply!

However, I'm sorry that I don't think this resolved my issue. May I explain my test with more detail?

First, I activated the reverse mode and observed that the evaluation board’s VAC output was at 12V.
Next, I powered on the connected 24V external adapter. At this point, the VAC voltage rose to 24V; however, monitoring through BQstudio showed that the reverse mode had not been disabled.

I understand that you mean the reverse mode is not actually activated at this time, but I would like to know if it is also normal for EN_REV to remain enabled under these conditions?

+1 Taylor 9 天前回复 TIanyi Ji

TI__Mastermind 36315 points

Hi,

Yes, this would be normal. The device cannot automatically exit the reverse mode. It is recommended to set EN_REV=0 to exit reverse mode.

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BQ25856EVM: question about auto-reverse mode