LM2596: Difference observed in switching frequency for LM2596-ADJ

Rik Paul

Prodigy 50 points

Part Number: LM2596

Hi,

I am testing LM2596-ADJ Chip in Lab using the following board module,

I purchased this step-down module from here

The lab reading shows the switching frequency of the device to be around 49-50 kHz in any load condition it is tested (checked for 500mA - 1.2A). 2 Test reading snaps given below.

But the datasheet(datasheet link) says that the frequency of operation is around 150kHz

Could you please explain this difference in behavior?

over 6 years ago

0 Samuel Jaffe over 6 years ago

TI__Mastermind 25590 points

Rik,

The part should operate at 150kHz +/-15% as specified in the datasheet.

Your images did not attach. Please try again so I can take a look.

-Sam

0 Samuel Jaffe over 6 years ago in reply to Samuel Jaffe

TI__Mastermind 25590 points

Rik,

I have not heard back from you. Please reply or post again if you are still having issues.

Thanks,
-Sam

0 Rik Paul over 6 years ago in reply to Samuel Jaffe

Prodigy 50 points

Hi Sam,

I have checked several times , but can see the same reading on my oscilloscope. Do you guys have any EVM for this chip??

0 Samuel Jaffe over 6 years ago in reply to Rik Paul

TI__Mastermind 25590 points

Rik,

Here's the link to the EVM on our online store.

Please try to attach the images again. They did not go through the first time.

-Sam

0 Rik Paul over 6 years ago in reply to Samuel Jaffe

Prodigy 50 points

Hi Sam,

PFA the image again.

0 Samuel Jaffe over 6 years ago in reply to Rik Paul

TI__Mastermind 25590 points

Rik,

That's interesting. It may be a part disguised as the LM2596 or they may be doing something funny with the part. Either way you would have better luck getting in contact with the designer of that module directly.

-Sam

0 Rik Paul over 6 years ago in reply to Samuel Jaffe

Prodigy 50 points

Hi Sam,

If there is something wrong about the chip, then can I get a evm module of LM2596-ADJ from TI? I might then perform the test once again & verify the same.

Thanks,

Rik

0 Samuel Jaffe over 6 years ago in reply to Rik Paul

TI__Mastermind 25590 points

Rik,

Yes I believe that is a smart course of action. Here's the link to the EVM.

-Sam

Power management

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LM2596: Difference observed in switching frequency for LM2596-ADJ