LMR14010A: ripple reduction in eco-mode

Genius 16495 points

Part Number: LMR14010A

Hi all

My customer has a design using the LMR14010A, the specification is:

5V .... 32V => 3.3V/50mA, the device is mostly running in eco-mode.

They see a ripple of 40mV ... 60mV, which is too high for their application and is affecting the ADC accuracy.

What measures can you recommend to reduce the ripple in eco-mode ?

.... or is there another comparable device at comparable cost that you would recommend using ?

Please find the schematic copied below.

Best regards

Ueli

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over 3 years ago

0 Denislav Petkov over 3 years ago

TI__Mastermind 19461 points

Hi Ueli,

They can try reducing the inductor value and force the IC to switch "more often" in eco-mode.

Depending on their ripple target for the ADC and if they want to stay in eco-mode, they may have to try an LDO after Buck regulator.

Cheers,
Denislav

0 Ue over 3 years ago in reply to Denislav Petkov

TI__Genius 16495 points

Hi Denislav

Thank you for the quick reply.

Would a higher value output capacitor help here as well ?

Best regards

Ueli

0 Denislav Petkov over 3 years ago in reply to Ue

TI__Mastermind 19461 points

Hi Ueli,

It is worth a try, although I don't know how much ripple is too much in their case.

Another idea is to do some post filtering with another small L and C. This can be tricky depending on how much the frequency we try to filter varies over the load.

Regards,

Denislav

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LMR14010A: ripple reduction in eco-mode