LM2903B: use same PCB footprint for SOT-23-THIN 8 (DDF) and WSON 8 (DSG) ?

AnBer

Part Number: LM2903B

Team,

Is it possible to use the same PCB footprint in order to solder SOT-23-THIN 8 (DDF) or WSON 8 (DSG) ?

Do we have example of PCB footprint that could be compatible with both packages?

Sine the dimension do not appear in the https://www.ti.com/lit/pdf/mpds308 WSON description it is difficult to compare both.

Thanks in advance,

over 2 years ago

0 Paul Grohe over 2 years ago

TI__Guru 53826 points

Hello AnBer,

I don't think so..the pitches are different. I have not tried it and have not heard of anyone else doing it.

See the attached drawing for the DSG dimensions:

/cfs-file/__key/communityserver-discussions-components-files/14/DSG0008A_5F00_LM2903B.pdf

WSON's need to have appropriately sized pads for proper fillets and to prevent wicking, otherwise the joints may be unreliable. If you do have to make some strange sized pads, I would double-check with your PCB vendor.

0 Paul Grohe over 2 years ago

TI__Guru 53826 points

Boy, it is close... Just depends on how flexible your PCB fab is about solder mask spacing. You could possibly optimize the DDF pad sizes.

I would be very concerned about the wicking of solder out onto the larger pads. Too much solder on the pads can cause the DSG to lift.

I would be concerned about the DSG reliability.

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LM2903B: use same PCB footprint for SOT-23-THIN 8 (DDF) and WSON 8 (DSG) ?