LMR23610: Current Draw instability

Anthony Schnelle

Part Number: LMR23610

Hello,

I have been investigating this issue more. By increasing the inductance from 15uH to 22uH the current draw is stabilized. Reading the datasheet it shows that 15uH is recommended for 3.3V outputs. Attached is a schematic of the circuit in question. buck page.pdf

over 4 years ago

0 Frank De Stasi over 4 years ago

TI__Guru 57555 points

Hello

If the 22uH works for you, then that value should be OK.

Thanks

0 Anthony Schnelle over 4 years ago in reply to Frank De Stasi

Prodigy 30 points

Frank,

Is there any reason that the 15uH would cause unstable current draw. If so why would it be suggested in the datasheet. It is only a very few LMR23610 chips that seem to have this behavior with the 15uH inductors. Does any one have any insight as to why there would be a difference between chips?

Anthony

0 Frank De Stasi over 4 years ago in reply to Anthony Schnelle

TI__Guru 57555 points

Hello

There will always be difference between devices due to normal

manufacturing tolerances. For this device the inductor value will have a small influence

on the full load performance but more influence at light loads.

If you can give us your schematic and your input, output, and load conditions,

along with wave-forms of the input current for both "bad" and "good" conditions

then we may be able to help explain further.

Thanks

0 Frank De Stasi over 3 years ago in reply to Frank De Stasi

TI__Guru 57555 points

Hello

I will close this post due to inactivity.

Thanks

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LMR23610: Current Draw instability