UCC21520-Q1: UCC21520 package dimensions

Yangbo

Intellectual 1690 points

Part Number: UCC21520-Q1
Other Parts Discussed in Thread: UCC21520

Hi team,

in the datasheet of UCC21520, I am wondering the meaning of the content in red box as below. Thanks a lot!

Regards!

Yangbo

over 7 years ago

0 Don Dapkus over 7 years ago

TI__Guru**** 189401 points

Hi Yangbo,

These are notes about the mechanical dimensioning of the package.

I've asked my colleague to help you with exactly what they refer to. He will get back to you on Monday, Dallas time.

0 Yangbo over 7 years ago in reply to Don Dapkus

TI__Intellectual 1690 points

Thanks Don.

0 William Toth over 7 years ago in reply to Yangbo

TI__Expert 3555 points

Hi Yangbo,

The symbol you are referring to is the "Geometric dimensioning and tolerancing" or "GD&T", and is essentially the tolerance of the pin location compared to the virtual ideal planes defined by A B and C allowing manufacturing that is repeatable based on proper (mechanical assembly) function.

The recommended footprint takes this into account and can be used as is. For more details here are two resources:

Definition:
wikipedia.org/.../Geometric_dimensioning_and_tolerancing

Basics with examples, the video also discusses why this notation is used instead of coordinates to locate the feature:
www.gdandtbasics.com/.../

Regards,
Will Toth

Interface

Interface forum

UCC21520-Q1: UCC21520 package dimensions