PF8121 Efficiency Calculation

[tom_perman]

Hi,

I am looking to reduce power consumption on an existing design which uses the PF8121. One area considered is the efficiency of the PF8121 PMIC, as affected by the choice of inductor. It was proposed that we could increase the physical size, therefore reducing DC resistance, of the inductor used with the PMIC. We currently use Inductor Murata DFE252012F-1R0M=P2, which does meet the design guidelines, however it has been suggested we can do even better with a different inductor.  

Looking on the NXP website i could not obviously see any simulation models or simulation tools, which would allow the affect of changing the inductors on PMIC efficiency to be evaluated. Are there any such tools/resources available?

Thanks,

Tom 

[guoweisun]

We don't suggest your change the value of inductor,you can select the DCR smaller inductors in your system under same value condition.

[tom_perman]

Hi,

This may not have been clear, but I am proposing to do exactly what you suggest. I am proposing to change the inductor for a different part with the same inductance, but smaller DCR. 

What I wanted to estimate is for a given reduction in DCR what the impact on efficiency would be. I was wondering whether there are any models/tools to help with this. 

Thanks,

Tom

[guoweisun]

Firstly we don't have simulation model for this device,the smaller the better about DCR of inductor.