LMR33630: What is the reason for the load scale-up rate?

Hi Sveinn

This is required for frequency foldback at light load condition, the higher the Vout, the lower the Error Amp output which will drive the switching clock to more lower end.

B R

Andy

Thanks, What about fixed-frequency ICs? It seems that the larger the load, the lower the output voltage.

And your common name is Andy (Wide Vin) Chen? I would like to learn more about this issue to you.

B　R

Sveinn

Hi Andy, why " The lower the Error Amp output which will drive the switching clock to more lower end " Can you explain it in conjunction with the block diagram?

B R 

Sveinn

Hi Sveinn,

This is behavior of PFM version converter, The Fixed PWM version converter will regulate output more tightly.

Sorry that this control loop was not shown on block diagram because of proprietary IP, you may found some introduction on its data sheet.

B R

Andy

Hi Andy,

Thank you very much for your detail reply.

But I still have some doubts about FIX PWM version converter. In the actual product, we also see higher load, Lower Vout, Is this really just because of line loss ?

B R

Sveinn