LM5155: ILOAD overcurrent issue

user5883945

Part Number: LM5155

supply voltage : 3.3V

When VLOAD＜60V, ILAOD<100mA;

When VLOAD≥60V, ILAOD ≈ 400mA;

The use of dry battery power, not connected to the load when the current is so large, can not be used normally, there is a way to make the current down to the normal range? tks!

over 5 years ago

0 Garrett Roecker over 5 years ago

TI__Mastermind 21720 points

Hello user5883945,

Thanks for reaching out with your question and for considering the LM5155 in your application.

Can you please post the schematic you are working with? Are you trying to limit the output current to 100mA?

Thanks

Garrett

0 user5883945 over 5 years ago in reply to Garrett Roecker

Expert 1606 points

Hi Garrett:

I only use the dry battery power, 100mA is also very large, of course, I hope the current is as small as possible, the no-load current should be close to zero.

here is my SCH.

0 Garrett Roecker over 5 years ago in reply to user5883945

TI__Mastermind 21720 points

Hello,

To clarify, you want limit the input current to 100mA? The input current is going to be based on the output current of the controller. I am not one hundred percent clear on what the questions is.

-Garrett

0 user5883945 over 5 years ago in reply to Garrett Roecker

Expert 1606 points

Hi：

The questions is no-load output overcurrent,

output voltage<60V，no-load current≈100mA,

output voltage>60V，no-load current≈400mA,

0 Garrett Roecker over 5 years ago in reply to user5883945

TI__Mastermind 21720 points

User5883945,

If you are trying to lower the operating current the best way to do this is to lower the switching frequency and the gate charge of the selected MOSFET.

Please be aware if the converter is boosting from 3.3V to 60V the MOSFET will have to switch every cycle consuming current.

Thanks,

Garrett

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LM5155: ILOAD overcurrent issue