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cameronokeeffe
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DA9062 Inductor

Hi Team,

I am currently working on a lower power application using your DA9062 PMIC and I am hoping to improve the design's efficiency and reduce transients in the system.
The PMIC's datasheet specifies a 1uH inductor for all four of its bucks - is this inductance restricted because of limitations with the internal circuitry or can it be adjusted to improve the current ripple for systems with a lower max current draw requirement?

Our system has a max current draw of 0.5A, with Vin(max) of 4.2V and Vout(max) of 1.25V. 
In out max loading condition, using a 1uH inductor, the inductor ripple current is ~40-60% of current draw. Can I increase the inductance to say 2.2uH to reduce to the ripple current to ~20-30% in the max loading case?

Cheers,
Cameron 

Device: 
ED_Dialog
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Hello Cameron,

Hello Cameron,

That’s a very good question. I will speak with the PMIC application engineers about this.

kind regards,

Elliott 

ED_Dialog
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Hello Cameron,

Hello Cameron,

I have spoken with the team about this. We see no reason why a 2.2uH inductor cannot be used, however we cannot guarantee the performance of the bucks with the datasheet. I think it should also be noted that the performance of the buck when it is in PFM will be significantly different with 2.2uH rather than the 1uH.

 What problems are you see with using 1uH?

 Kind regards,
Elliott Dexter

cameronokeeffe
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No specific problem, just

No specific problem, just exploring optimization options.