LMR14030-Q1: Question about output capacitor

Chase Jeong

Mastermind 7505 points

Part Number: LMR14030-Q1

Tool/software:

Dear TI experts,

My customer have a question about designing LMR14030SSQSSARQ1.

They do not have enough PCB space, so they want to know ceramic capacitor in the output.

Please check the schematic first.

Input voltage is 12V, output voltage is 5V, output current is about 150mA.

And they want to change C10, C11 capacitors to 22uF 10V X7R K 3216 Q x 2.

Could you confirm that this change would be okay or not?

Please check this issue. Thanks.

Best regards,

Chase

3 months ago

0 Dino Maslic 3 months ago

TI__Expert 5370 points

HI Chase,

Can you send the specific part number for the caps they want to use? Want to check how much the capacitors will de-rate down to.

Thanks,

Dino

0 Chase Jeong 3 months ago in reply to Dino Maslic

Mastermind 7505 points

Dear Dino,

Thank you for your support.

Capacitor is the part of Murata, I attach the spec. sheet.

GCM31CR71A226KE02-01A.pdf

Best regards,

Chase

0 Dino Maslic 3 months ago in reply to Chase Jeong

TI__Expert 5370 points

Hey Chase,

According to Murata, at 5V bias the caps will derate ~42%. Meaning that the 2x22uF will now have a derated total capacitance of ~25.5uF. Think this is a bit too low, would the customer consider using higher voltage rated capacitors, or up the capacitance values to something like a 47uF?

Thanks,
Dino

0 Chase Jeong 3 months ago in reply to Dino Maslic

Mastermind 7505 points

Dear Dino,

Thank you for your support.

What value do you recommend if I choose higher voltage rated capacitor? 16V is enough? or higher value?

Best regards,

Chase

0 Dino Maslic 3 months ago in reply to Chase Jeong

TI__Expert 5370 points

16V would be better, this is what is generally used for 5VOUT. Higher voltage rating you go the less derating you will get.

Thanks,

Dino

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LMR14030-Q1: Question about output capacitor