LMR23630-Q1: boot resister

Masatoshi Oguri

Part Number: LMR23630-Q1

Hello,

Do you think a boot resistor, which is a small register in series to CBOOT, is effective to suppress EMI for this device?

The concern here is a too large boot register can confuse the control of the regulator IC.

Thank you.

Regards,

Oguri (TIJ automotive FAE)

over 7 years ago

0 Samuel Jaffe over 7 years ago

TI__Mastermind 25590 points

Oguri-san,

You're describing a method of slew-rate control. Slew-rate control is a good method of reducing EMI as described in this blog post. Your method would control the slew rate of the high-side FET which should help EMI.

-Sam

0 Ambreesh Tripathi over 7 years ago

TI__Expert 6860 points

Oguri-San ,

As Sam mentioned , CBOOT resistor helps in slowing down the turn on of the high side FET and thereby reducing the dv/dt . Its an effecting way of dealing EMI .

The only concern would be the fact that the large value of the BOOT resistor may trigger BOOT UVLO and thereby may disable the HIGH SIDE FET drive .
What value of BOOT resistor cusotmer is adding in the design ?

---Ambreesh

0 Masatoshi Oguri over 7 years ago in reply to Ambreesh Tripathi

TI__Expert 4780 points

Hi Ambreesh,

Thanks a lot.
The resistor value is not determined yet.

Oguri

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LMR23630-Q1: boot resister