LM5155: peak source current with external VCC?

Aki Li

Part Number: LM5155

Tool/software:

When customer uses external VCC, what is the peak source current it can support? How to calculate the higher value it can support?

3 months ago

0 Moritz 3 months ago

TI__Genius 9865 points

Hi Aki,

thanks for reaching out.

The peak value depends on the saturation current of the internal FET and does not vary very much for this device.

The max. possible peak sourcing current with external VCC will be around 2A.

Best regards

Moritz

0 Aki Li 3 months ago in reply to Moritz

TI__Expert 8975 points

Moritz,

Thank you. Customer reported another issue that they tried to use mathcad to calculate the Ccomp, showed in "How to Design an Isolated Flyback Using the LM5155", and found the unit of the results were not aligned with the document.

Could you please help check it?

0 Moritz 3 months ago in reply to Aki Li

TI__Genius 9865 points

Hi Aki,

in this formula, P is missing:

Best regards

Moritz

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LM5155: peak source current with external VCC?