BQ76952: Why there is an diode between the PACK+/- in TI reference design?

Hello Cheng,

Please look at my answer here.

Best regards,
Abhijith

It didn't answer the question at all. If reverse charger attached, the diode will conduct and it has nothing to do with other circuitry. The diode will keep conducting and flowing current if the charger is reversely attached and not removed.

Hi Cheng, apologies for the misunderstanding.

As to why a diode is used here, there are two common reasons:

1. As a freewheeling diode to help against inductive kickback. In the image you attached ES3D-E3/57T is used for this purpose.

2. As a TVS/ESD diode: Some designs use parts like SMCJ60A here.

Thanks,
Abhijith

Thanks for clarify. So if reverse polarity protect for external charger is required, then the diode ES3D-E3/57T can't be put in here, correct? This is more for inductive negative spikes.

1. The app note never mentioned the direct diode between the PACK+/- for reverse polarity. 2. The diode is connected directly between the PACK+/-, if the reverse voltage is present on the PACK+/-, then the diode will conduct. How to interrupt the current path as they're directly connected?