TPS75801KTTR TO-263 land pattern?

Antimatter

Intellectual 430 points

Other Parts Discussed in Thread: TPS758

Hi,

The land pattern of the LDO TPS75801KTTR (TO-263 package) seems not fit the actual layout of the exposed thermal tab.

The exposed shape on the back where the solder cream needs to be is not a square.

Is the land pattern right?

How does the LDO need to be layout on the land pattern?

The package information is at page 24 and the land pattern is on page 25 of the datasheet.

For example, I'm expecting a land pattern like for LP38500:

over 9 years ago

0 Ryan Eslinger over 9 years ago

TI__Guru 55940 points

Hi ,

Please note that the recommended dimensions for the land pattern covers the entire exposed metal area on the bottom of the device. The other land pattern that you provide simply cuts out a rectangle from the bottom two corners of the recommended land pattern for TPS758.

Very Respectfully,
Ryan

0 Antimatter over 9 years ago in reply to Ryan Eslinger

Intellectual 430 points

OK, so it's not a problem the land pattern covers the package itself at the places where is no metal exposed (the black parts)?

0 Ryan Eslinger over 9 years ago in reply to Antimatter

TI__Guru 55940 points

Hi ,

Correct. The black part is non-conductive so there is no problem.

Very Respectfully,
Ryan

0 Antimatter over 9 years ago in reply to Ryan Eslinger

Intellectual 430 points

Thanks for the quick response! OK, yes it's not conductive. Sorry, I was thinking about the solder paste for reflow soldering. Isn't no problem the paste is under the black part? Because the datasheet provides the same Stencil design size as the board layout.

0 Ryan Eslinger over 9 years ago in reply to Antimatter

TI__Guru 55940 points

Hi ,

Correct, there is no issue with having some solder paste below the non-conductive portion of the package. The example stencil dimensions are actually slightly smaller than the example board layout to accommodate some spreading of the solder paste.

Very Respectfully,
Ryan

0 Antimatter over 9 years ago in reply to Ryan Eslinger

Intellectual 430 points

One more question, is the thermal pad already connected to ground internally? Should the thermal copper plate I've added connected to the ground plane?

Thanks,

Peter

0 David Hopkins over 9 years ago in reply to Antimatter

TI__Expert 8905 points

Hi Peter,

I would recommend connecting the thermal plane to the ground plane. As this is an older device I do not know if the thermal pad is connected to ground internally but on most LDOs they are shorted together.

Regards,
David

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TPS75801KTTR TO-263 land pattern?