LMR14006: Light load operation of converter

Hi

Yes it is in DCM mode. And the device senses the peak current of HS, when the iL rise up and hit a specific value(set by the device,  fixed), The HS shut off. 

For the HS to turn on, it senses the VFB, when VFB decline and hit the VREF, the HS turns on.

please let me know if there are other questions.

Thank you

I have another query : what formula shall I used to verify minimum on time calculation in DCM ? 

I am using this converter for 12V in to 5V out requirement and there at light load and full load condition with minimum 95ns I want to make sure votage should not rise above 5V.

Hi 

Since the iL rise slew rate is (Vin-Vo)/L, and will rise up to ipk_min, so the ton will be ipk_min*L/(Vin-Vo). I think the ipk_min is not specified in the LMR14006 datasheet. 

The Vo will not rise above 5V since it will monitor the VFB and will not start another cycle until VFB is as low as VREF. Are you worrying about the output ripple voltage?

Thank you.

Hello,

I am worry abot light load DCM operation. Because of minimum on time this output voltage should not rise above 5V in light load as this buck operating in fixed frequency mode.

Thank you.

Hi Vaibhav

During the light load, it doesn't operate under fixed fsw then, the fsw will decrease. And it should not rise above 5V.

Thanks.