SN54HC541: Datasheet Thermal Resistance Value increased from Revision D to Revision E

Shinichi Inoue

Guru 20051 points

Part Number: SN54HC541

Dear Specialists,

My customer is using SN54HC541 and has a question.

I would be grateful if you could advise.

According to the PCN20220511003_202205191, thermal resistance is increased Revision D to Revision E, DB was 90.2 is now 122.7, DW was 77.5 is now 109.1, N was 45.2 is now 84.6, NS was 72.8 is now 113.4, PW was 98.3 is now 131.8.

On the other hand, there is no anticipated impact.

Could you please advise how to think about this result.

I appreciate your great help in advance.

Best regards,

Shinichi

over 2 years ago

0 Clemens Ladisch over 2 years ago

Guru 264040 points

The PCN says that "There are no changes to the actual device." So if your boards worked previously, they will continue to work.

The drive strength of HC devices is so low that it is unlikely that power dissipation will become a concern.

0 Shinichi Inoue over 2 years ago in reply to Clemens Ladisch

Guru 20051 points

Hi Clemens,

Thank you for your reply.

I understand there is no problem.

Could you please advice why thermal resistance value has changed.

Does the test condition of thermal resistance change?

I appreciate your great help and cooperation.

Best regards,

Shinichi

0 Clemens Ladisch over 2 years ago in reply to Shinichi Inoue

Guru 264040 points

The values in the old datasheet revision were not correct. I am not a TI employee and do not know the reason why.

0 Shinichi Inoue over 2 years ago in reply to Clemens Ladisch

Guru 20051 points

Hi Clemens,

Thank you for your reply.

I'd like to know the background of changing thermal resistance.

Hi TI'er

Could you please let us know why the thermal resistance has changed.

Does the test condition of thermal resistance change?

I appreciate your great help and cooperation.

Best regards,

Shinichi

+1 Sebastian Muriel over 2 years ago in reply to Shinichi Inoue

TI__Genius 14250 points

Hi Shinichi,

Two years ago, TI migrated to a new process. There is a new die and the devices use roughened leadframes. The device still meets all of the datasheet specifications from the existing datasheet. This is an older device, so our thermals process has been improved over the years.

Sebastian

0 Shinichi Inoue over 2 years ago in reply to Sebastian Muriel

Guru 20051 points

Hi Sebastian,

Thank you for your reply.

I'd like to confirm your comment.

What does the improvement in the thermal process?

Theta j-a is worse than before.

I appreciate your great help and cooperation.

Best regards,

Shinichi

+1 Sebastian Muriel over 2 years ago in reply to Shinichi Inoue

TI__Genius 14250 points

Hi Shinichi,

Sebastian Muriel said:
This is an older device, so our thermals process has been improved over the years.

Just to clarify I meant the process of obtaining our thermals has been improved over the years, not that the thermal performance for this device has improved.

Regards,
Sebastian

0 Shinichi Inoue over 2 years ago in reply to Sebastian Muriel

Guru 20051 points

Hi Sebastian,

Thank you for your reply.

I understand.

I'll share this information with the customer.

I appreciate your great help and cooperation.

Best regards,

Shinichi

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SN54HC541: Datasheet Thermal Resistance Value increased from Revision D to Revision E