BQ25606: Output voltage Jumping issue when no battery is present.

Drauzio Oppenheimer

Part Number: BQ25606
Other Parts Discussed in Thread: BQ24266

As Jacob pointed, if the battery is not connected and you keep the CE low, the VSYS keeps jumping from 3.7V to 4.2V as it sees the BAT as 0V. Is there any way to prevent this without manually enabling and disabling the CE pin ?

For example, if BAT is below 2V, you don't enable charge mode. Is it possible inside the component ? without external discrete components ? Because as I used the BQ24266, it does behave the right way, not like the new BQ25606.

Thanks.

over 4 years ago

0 Jeff F over 4 years ago

TI__Guru*** 143880 points

Hi Drauzio,

The charger was designed assuming that without a battery, the TS pin would fault and disable charge. Taking TS pin high/low to force battery COLD/HOT state disables charge the same as taking /CE high.

Regards,
Jeff

0 Drauzio Oppenheimer over 4 years ago in reply to Jeff F

Prodigy 20 points

So:

1 - It's not possible to disable the TS function, as in the BQ24266 ? That's a downgrade for me.
2 - With the TS using the default resistors, the BQ25606 enters in fault mode without battery, recognizing a "hot" temperature because the TS is 30/35 of VREGN so the output regulated voltage is 3.7V, not 4.2V in this mode. That's how it's supposed to work, really ? Why make such poor changes from the previous version ? It's just a worst product.

0 Jeff F over 4 years ago in reply to Drauzio Oppenheimer

TI__Guru*** 143880 points

Hi Drauzio,

For battery safety, the systems and design team felt that TS should not be disabled by tying high to REGN/DRV like BQ24266.

The BQ25606 is a descendant of the BQ2419X, BQ2429X and BQ2589X families, all of which have similar TS and battery removal functionality.

Regards,
Jeff

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BQ25606: Output voltage Jumping issue when no battery is present.