BQ25713: Pass Through Mode (min duty cycle)

Alberto Doronzo

Part Number: BQ25713

Hi,

what is the maximum duty cycle allowed in pass-through mode?

The block diagram and description seem to point to a bootstrap method to charge up the gate voltage for the n-fet, which requires the low side FET to be turned on to allow the bootstrap capacitor to charge - please correct me if my interpretation is incorrect.

Thank you!

Best regards,

Alberto

over 7 years ago

0 Yipeng Su over 7 years ago

TI__Prodigy 420 points

The two high side FETs are kept always on, until the bootstrap caps need to be refreshed. Then the low side FET is turned on for a very short period to recharge the bootstrap caps.

Roughly, the low side FET turn on frequency is around 1kHz.

0 Alberto Doronzo over 7 years ago in reply to Yipeng Su

TI__Expert 4840 points

Hi Yipeng,
thanks for the quick reply.
Ok, bootstrap cap refresh about 1khz; how long does the LS stay on? (is there a min on-time?).
Thank you!
Regards,
Alberto

0 Yipeng Su over 7 years ago in reply to Alberto Doronzo

TI__Prodigy 420 points

During bootstrap cap refresh, the LS on time is around 100ns~200ns.

Power management

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BQ25713: Pass Through Mode (min duty cycle)