TMP302: Layout Recommendation

Keith Keller

Expert 7070 points

Part Number: TMP302

Hello,

We're using the TMP302 in an application and getting varying accuracy results.

Looking for some layout suggestions.
Which pin on the IC is used for temperature measurements?
Not able to connect up any pins on the IC to the high temperature copper pour.

Current layout (below)

Proposed updated layout (below)
Pour copper under IC and use VIAs to connect pins to internal layers
Pull away copper on layers 2, 3, and 4 under the IC

Thank you for your help, Keith

over 1 year ago

0 HarryG over 1 year ago

TI__Expert 3840 points

Hello Keith,

Thank you for your question. What is the end application for this device if I may ask? Also, are you trying to measure ambient temperature or the PCB's temperature?

Regards,

Harry

0 Keith Keller over 1 year ago in reply to HarryG

TI__Expert 7070 points

This is measuring a terminal in a battery. Batt+ pour is the desired node to measure.

0 HarryG over 1 year ago in reply to Keith Keller

TI__Expert 3840 points

Hello Keith,

As far as the layout is concerned, it looks fine. The only thing I would suggest is possibly adding some cutouts around the switch to isolate from other potential heat sources. I've attached a guide below that provides helpful information on this (start from page 25).

Layout Guide Here

Could you please elaborate on what you mean when you say you're getting varying results? Does this mean the switch triggers at random points?

Regards,

Harry

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TMP302: Layout Recommendation