LM61460-Q1: Quiescent Current of LM61460.

Tony Strachan

Part Number: LM61460-Q1

Hello,

I have a LM61460AAS and a LM61460AFS on two of my designs. The AAS version draws very little quiescent current under no load as expected (~60uA). However the AFS version draws approximately 7mA which is far more than I was expecting. I know the AFS version is fixed FPWM but should it get this high with no load?

Thanks,

Tony

over 1 year ago

0 Jimmy Hua over 1 year ago

TI__Mastermind 47060 points

Hi Tony,

Yes the AFS is running in FPWM mode which usually pulls more current because it is fixed switching. the AAS is auto-mode and switching is scaled back at lighter loads which results in less current pull. This is also the reason why the AAS variant will have higher efficiency than AFS at lighter load.

Regards,

Jimmy

0 Tony Strachan over 1 year ago

Prodigy 10 points

Hi Jimmy,

Thanks for the reply. I realised that the AFS would draw more current than the AAS version but would 7mA compared to 7uA be correct? I wouldn't have thought it would have drawn that much more but maybe it does?

Cheers,

Tony

0 Jimmy Hua over 1 year ago in reply to Tony Strachan

TI__Mastermind 47060 points

Hi Tony,

That sounds reasonable and to be expected given that AFS is constantly switching at lighter loads.

Regards,

Jimmy

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LM61460-Q1: Quiescent Current of LM61460.