LM22675-5.0, How much is minimun load current?

Shinichi Inoue

Guru 19671 points

Dear Specialists,

My customer is evaluating LM22675-5.0

He is using from a few microamp to a few miliamp.

When power is up, and then a few second later, output voltage became 8V despite setting or 5V.

As a trial, he added a 200ohm resistor at the output, the voltage went back to normal 5V.

His question

how much is minimum load current of LM22675-5.0?

I appreciate your great help.

Best regards,

Shinichi

over 7 years ago

0 Anston Lobo over 7 years ago

TI__Genius 16025 points

Hi Shinchi,

Try minimum loading of 1 to 5mA. I haven't seen this issue on this part, but if you can provide the Vin and feedback divider values I can check this on the bench.

Thanks,
Anston

0 Shinichi Inoue over 7 years ago in reply to Anston Lobo

Guru 19671 points

Dear Anston

Thank you for your reply.

I am going to feedback your answer to the customer.

Also, I am going to confirm Vin and feedback resistor value.

Could you please wait for a while.

I appreciate your great help.

Best regards,

Shinichi

0 Shinichi Inoue over 7 years ago in reply to Shinichi Inoue

Guru 19671 points

Dear Anston

The customer sent me the schematic.

Could you please see attached file and test on the bench.

There are no feedback resistor because LM22675-5.0 doesn't need feedback resistor.

If you have any question, could you please contact me.

I appreciate your great help.

Best regards,

Shinichi

schematic LM22675MR-5.0.pdf

0 Anston Lobo over 7 years ago in reply to Shinichi Inoue

TI__Genius 16025 points

Shinichi,

The boot cap value is too high! That could be the reason why Vout drifts to 8V.. Can you lower C210 from 1uF to 10nF.

Let me know,
Thanks,
Anston

0 Shinichi Inoue over 7 years ago in reply to Anston Lobo

Guru 19671 points

Dear Anston

Thank you for your reply.

I'll feedback the boot cap is too big to the customer.

If he has additional question, I will consult with you.

I appreciate your great help.

Best regards,

Shinichi

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LM22675-5.0, How much is minimun load current?