LM5156-Q1: LM5156-Q1 boost converter calculation sheet is something wrong.

Lin Vast

Part Number: LM5156-Q1

My design is Vin=8~16,Vout=25,Iout=0.18,eff=90%,fsw=440k current ripple=30% in CCM mode.

The value of ILpk shows 1.53.

Iin_max is 25*4.5/8/0.9=0.68,if the value of ILpk is 1.53,it means the ripple current of L is 0.85,so the ripple ratio is 125%,but my setting is 30%.

over 1 year ago

0 Lin Vast over 1 year ago

Prodigy 250 points

Correction.

Iin_max is 25*0.18/8/0.9=0.625,if the value of ILpk is 1.53,it means the ripple current of L is 0.905,so the ripple ratio is 145%,but my setting is 30%.

0 Feng Ji over 1 year ago in reply to Lin Vast

TI__Mastermind 22810 points

Hi Lin,

Can you share the calculation sheet? I filled these data in the calculation sheet and ILpk shows 0.67A, which should be correct.

Best Regards,

Feng Ji

0 Lin Vast over 1 year ago in reply to Feng Ji

Prodigy 250 points

Hi,

I know where the problem is now because I didn't set the Ls value. The ripple current value is not calculated based on the recommended value, but rather based on the values I have set.

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LM5156-Q1: LM5156-Q1 boost converter calculation sheet is something wrong.