LM25011: supercapacitor charger

Marco Merletti

Part Number: LM25011

Hello,

I took over Alen Barisic (I was working with him on this issue) post with additional information.

LM25011 is charging supercap to target Vout. After some minutes it does not regulate anymore and there is no way to force restart, power off neither.

The only condition that can trigger restart is when Voltage on supercap discharge down to less than 3V. In this condition Vss go low and the circuit can be re.trigger with a power off/on

over 1 year ago

0 Richard Fu22 over 1 year ago

TI__Mastermind 21500 points

Hi Marco,

Let me pass this on to the engineer in charge of E2E for the next month. But to echo the previous thread from Alen, was there a case where input voltage was lower than the output voltage of the super cap after charge?

Regards,

Richard

0 Marco Merletti over 1 year ago in reply to Richard Fu22

Prodigy 20 points

Hello Richard,

thanks for your reply. Yes, there could be a case that supercap is partially charged and I want to refresh charge to full.

0 Richard Fu22 over 1 year ago in reply to Marco Merletti

TI__Mastermind 21500 points

Hi Marco,

In this case, I think what might happen is that the pre-charge device cannot pull SW node down enough to keep the bootstrap capacitor charged to maintain switching behavior. What you may try to do is reduce the feedback resistance in such a way that 1mA load at nominal Vout to keep minimum switching frequency higher and allow for constant refresh of bootstrap capacitor.

Regards,

Richard

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LM25011: supercapacitor charger