BQ24725: power supply for system switches from Battely to ADP

tateo yamashiro

Part Number: BQ24725

Hi,

We got a question from customer about bq24725.
Could you help us?

[Question]
When power supply for system switches from battery to ADP, BATDRV is OFF about 4msec before system voltage changes from battery to ADP. They suppose this phenomenon is protection to avoid ADP voltage apply to battery. Is their understanding correct? If their opinion is correct, how much is the variation of 4msec OFF time?

Best Regards,
tateo

over 8 years ago

0 Wang5577 over 8 years ago

TI__Guru 56650 points

We don't want ACFET and BATFET are turned on at the same time. That is correct.

The dead time is controlled by the external FET gate RC delay. bq24725x charger logic only keep 10us dead time. All other dead time comes from the FET gate RC delay.

0 tateo yamashiro over 8 years ago in reply to Wang5577

Guru 10890 points

Hi, Thank you for your support. We got additional question. Could you help us?

- How much is the variation of IBATFET and IACFET? They would like to know the maximum value.

They don't need guarantee. They will use it as reference.

Best Regards,

tateo

0 Wang5577 over 8 years ago in reply to tateo yamashiro

TI__Guru 56650 points

It is hard to give the maximum number because ATE doesn't check the maximum number. Also, I cannot understand why do they need the maximum number? The minimum number is meaningful for the external resistance calculation and turn-on speed calculation. How do they use the maximum number?

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BQ24725: power supply for system switches from Battely to ADP