LMR36503-Q1: bootstrap Rboot power dissipation calculation/formula

6351228

Prodigy 90 points

Part Number: LMR36503-Q1

Tool/software:

Dears,

Please tell us how to calculate LMR36503-Q1 bootstrap resistor Rboot power disspation and its formula.

we need to know it to select Rboot size and power rating.

Thanks.

Maguire

2 months ago

0 6351228 2 months ago

Prodigy 90 points

updated,

we will use LMR36503-Q1 to do 48V-to-3.3V application

Thanks.

0 Richard Fu22 2 months ago

TI__Mastermind 20300 points

Hi Maguire,

Please refer to this thread for power dissipation:

https://e2e.ti.com/support/power-management-group/power-management/f/power-management-forum/1060174/faq-tps546d24a-selecting-rboot-and-calculating-rboot-power-dissipation

To summarize, usually the power dissipation for Rboot is quite small, so an 0402 can be used. Usually, we do not recommend going above 10Ohms. The current standard is to start with 0Ohm and slowly increase, while examining on the bench. Usually for the LMR36503-Q1, a boot resistor is not necessary.

Thanks,

Richard

0 6351228 2 months ago in reply to Richard Fu22

Prodigy 90 points

Dear Richard,

got it, thanks

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LMR36503-Q1: bootstrap Rboot power dissipation calculation/formula