TPS43060: external 5V bias for BOOT pin

Sam Ting

Expert 3560 points

Part Number: TPS43060
Other Parts Discussed in Thread: TPS43061,

Hi team,

Is there any potential risks if we apply the external 5V bias for BOOT pin through Dboot as shown below? Thanks!

My customer wants to evaluate the GaN to replace high side conventional MOSFET and the suggested driving voltage is 5V.

Best regards,

Sam Ting

over 5 years ago

0 Helen chen over 5 years ago

TI__Mastermind 40080 points

Hi Sam,

This kind of connection is not suggested.

You can choose TPS43061, its VCC range is within 5.2-5.8V.

0 Sam Ting over 5 years ago in reply to Helen chen

TI__Expert 3560 points

Hi Helen,

Could you please explain why the connection is not recommended or any workarounds? Thanks!

We know TPS43061, but the customer wants to keep TPS43060 with the higher gate drive, 7.5V for low side conventional MOSFET.

Best regards,
Sam Ting

0 Helen chen over 5 years ago in reply to Sam Ting

TI__Mastermind 40080 points

Hi Sam,

I'm sorry to tell you that there's no work around.

If the internal VCC is 7.5V, the external VCC is 5V, then the internal VCC may works in the current limit mode as it is higher than the external VCC. And the voltage at the VCC pin may neither 5V nor 7.5V.

Is the GaN better than MOSFET?

0 Sam Ting over 5 years ago in reply to Helen chen

TI__Expert 3560 points

Hi Helen,

Yes, GaN devices don’t have a body diode so we can get higher efficiency due to lower reverse current and switching loss.
Thanks for your support!

Best regards,
Sam Ting

0 Helen chen over 5 years ago in reply to Sam Ting

TI__Mastermind 40080 points

Hi Sam,

Thanks for the information.Please suggest the customer use MOSFET. Actually the efficiency will not differ much since with body diode, the high side FET switching loss is near 0. This also helps the efficiency.

Good luck!

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TPS43060: external 5V bias for BOOT pin