CSD95430: Inductor selection

Lisa Xu

Intellectual 505 points

Part Number: CSD95430
Other Parts Discussed in Thread: TPS536C7

Dear TI team,

Please help confirm the power inductor(L276) and LSET resistor(R2328) selection is correct or not.Thanks

Input Voltage:12V

Output Voltage:3.3V

Maxium output current:6A

FSW: 1000KHZ

Inductor: L/1.5uH/20%/10.5A/9.7mohm

Lset resistor:R/715K/0603/1%

7485.design.pdf

over 1 year ago

0 Jack Su over 1 year ago

TI__Prodigy 410 points

Hi Lisa,

R2328 Lset should be 10.2kΩ/0603 [E96 Series 1%] for L=150nH.

There is another resistance should be changed. A_R1990 should be 1kΩ, and this is the description for PIN 38 IOUT as below:

"Output of current sensing amplifier. V(IOUT) – V(REFIN) is proportional to the phase current. All paralleled phases should have a 1-kΩ typical resistor from IOUT to a shared average node that is connected back to the controller. This average node is also fed back to the power stage through the IAVG pin."

Best regards,

Jack Su

0 Lisa Xu over 1 year ago in reply to Jack Su

Intellectual 505 points

Hi Jacky,

Please help cofirm if we can set the L=1.5uH,RLSET=715K, which the maxium output current=6A.

Thanks

0 Jack Su over 1 year ago in reply to Lisa Xu

TI__Prodigy 410 points

Hi Lisa,

Could you please explain more what do you mean? Thanks!

RLSET(R2328) should be 10.2kΩ/0603 [E96 Series 1%] for L=150nH instead of 715kΩ

Best regards,

Jack Su

0 Lisa Xu over 1 year ago in reply to Jack Su

Intellectual 505 points

Hi Jacky,

The maxium output current=6A, Vin=12V, Vout=3.3V, FSW=1000KhZ, base on the inductor selection guidline from TPS536C7 datasheet, the target inductor should be 1.3uH, so we chose the 1.5uH inductor.Thanks

0 Jack Su over 1 year ago in reply to Lisa Xu

TI__Prodigy 410 points

Hi Lisa,

Thanks for the information.

Yes, RLSET(R2328) should be 715kΩ for L=1.5uH.

Best regards,

Jack Su

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CSD95430: Inductor selection