LM5156HEVM-FLY: Transformer device on LM5156HEVM-FLY

Henry Wang3

Part Number: LM5156HEVM-FLY
Other Parts Discussed in Thread: LM5156

Hi Sir,

My customer would like to replace a new transformer device on LM5156HEVM-FLY Evaluation Module to verify the function the configuration is designed to provide a regulate output of 12 V at 2 A from an input of 18 V to 36 V.

Could you help to review whether the below jump wires are correct or not?

new transformer device VP4-0075-R

VP4-0075-R.pdf

original transformer device: Wurth Elektronik / 750317933

Wurth Elektronik_750317933.pdf

over 2 years ago

0 Brigitte over 2 years ago

TI__Guru 65170 points

Hello Henry,

In general the connection could work. Did you already use the quickstart calculator https://www.ti.com/lit/zip/snvc240 to check out if the transformer is within the right ballpark?

Best regards,
Brigitte

0 Henry Wang3 over 2 years ago in reply to Brigitte

Genius 3315 points

Hi Sir,

Sorry for the delayed response. Since the customer needs to check the transformer spec.

Could you help to review the below quickstart calculator table by the customer provided?

LM5155_56_Excel_Quickstart_Calculator_for_Flyback_Regulator_Design_9-36_12v_2a_1207.xlsx

The customer also provided the webench file, both files provided the different parameters of the component, which file do you advise them to use it?

VIN9-36V_Vout12_2A_SCH_BOM.pdf

0 Brigitte over 2 years ago in reply to Henry Wang3

TI__Guru 65170 points

Hello Henry,

I think the recommendation of the 2 is not too far off, Webench recommends 7.6uH and 2 as turns ratio, the calculator recommends 7.3uH and 2 as turns ratio. It just seems that the customer did not update the numbers in the yellow fields of the quickstart calculator.

I think the customer can use the connection as is, and can use the quickstart calculator to calculate the other component changes necessary for his updated transformer. But he needs to update the turns ratio in his transformer as he serializes 2 windings on the primary side and parallels 2 windings on the secondary side.

Best regards,
Brigitte

0 Henry Wang3 over 2 years ago in reply to Brigitte

Genius 3315 points

Hi Sir,

My customer used the new transformer device on LM5156HEVM-FLY Evaluation Module to verify the function, but they heard the transformer noise on the EVM. How to fix this issue?

Transformer spec:

VPH5-0155-R_22.3uH.pdf

LM5156 calculator table:

LM5155_56_Excel_Quickstart_Calculator_for_Flyback_Regulator_Design_9-36_12v_2a_1223.xlsx

Test waveform and Noise file:

test waveform_20221227.rar

0 Brigitte over 2 years ago in reply to Henry Wang3

TI__Guru 65170 points

Hello Henry,

I am sorry, I do not have a software on my mobile to extract a rar file. Could you put the data in a zip file instead, please?

Generally noise is coming from mechanical deformation of components and is in a frequency range that is far below the switching frequency. So you might check if the compensation does not fit the converter. Please check if you observe a type of oscillation on the output voltage or the transformer current.

Best regards,
Brigitte

0 Feng Ji over 2 years ago in reply to Henry Wang3

TI__Mastermind 22295 points

Hi Henry,

I can hear noise at 1.1A output. Is that your question?

Can you show more waveforms as the duty seems not stable.

Best Regards,

Feng Ji

0 Stefan Schauer over 2 years ago in reply to Feng Ji

TI__Guru 58461 points

Hi Henry,

I have not seen an update for the last 23 days, so I assume the questions are/or answered and the issue is solved.
I close this thread now. If there is still something open reply and the thread will get open again.
If you have any other question or of the thread gets locked, please open a new one.

Clicking the Resolved Button also helps us to maintain this forum.

Best regards,
Stefan

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LM5156HEVM-FLY: Transformer device on LM5156HEVM-FLY