LM2611EVAL: output current issue above 8 mA

Hello Ludovic,

Thanks for reaching out to us via e2e.

Please make sure that your lab supply is not running into a current limit. Please be aware that the necessary peak current can be much higher than the average current.

Sometimes, there are issues with the combination of different lab supplies, DC/DC converters and electronic loads.
Internally all of them are basically switch mode converters and some combinations show strange effects.

Therefore, please try using a different lab supply and load.

Best regards,
Harry

We improve the current limitation to 100 mA much more than the 30 mA required. It does not produce effects.

Best regards

Hi Ludovic,

LM2611EVAL can handle -5V/300mA, so please check your setup.

Have you checked input voltage when the problem happened? Are you using a resistor as the load?

Best Regard,

Feng Ji

Hi Feng,

   Yes I have chack the resitor value. It is correct. Besides, the power supply can handle such current. Nevertheless we limit the current at 80 mA in order to keep safe the EVAL.

Best regards

Ludovic Bacqué

We have a resitor and we use your EVAL.

Hi Ludovic,

Do you have the waveform of the input voltage?

You may limit the current at 1A.

Best Regards,

Feng Ji

Yes we have tested with a higher current limitation. It operate correctly. We are very suprising by the very high initial current!

 Do you have a line-up to propose to us in order to convert a +30V input voltage to a + 5V connected to the LM2611.

 In fact our input voltage is equaled to + 30 V and we need to voltages equalled to +5 V and - 5 V. Do you have any advices? 

Thank you.

Hi Ludovic,

You need a buck converter for +30V to +5V. You may start a new thread for recommended buck device.

For +5V to -5V, you may consider charge pump like LM2775 or LM2776.

Best Regards,

Feng Ji