This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

  • TI Thinks Resolved

HDC1080: Vias in DAP (PWSON package)

Prodigy 130 points

Replies: 2

Views: 21

Part Number: HDC1080

Hello,

the datasheet recommends vias in the DAP: (Page 20, Figure 18)

The routing and placement document recommends to use no vias: (page 15, 2.4 - 1st dot)

I have a 4-layer-pcb and there are no traces, pours, .. below the sensor on the bottom side. Should I use vias that connect to a second floating pad on the bottom side of the pcb to make better heat dissipation or should any copper on the bottom side be cut out?

Should the copper on the middle pcb layers be cut out or also used as via-connected floating pads?

thanks a lot in advance

mhein

  • In reply to Matze:

    Dear Matze - 

    I think the idea here is to keep thermal mass to a minimum - from limited experience with one other customer recently - they had same arrangement you describe, with multi-layers - in comparing that hardware in a chamber to other HDC devices, as the temp changed in chamber (going through a sweep cycle) it was same measurements, but lagged the others in response time - this would follow the concept of the higher the thermal mass, the response should be expected to be slower as compared to lower thermal mass, which would react faster to changes in the environment. We have a section in the document you attacehd (the  hdc1080 PlacementRouting.pdf attachment in previous post) that has section 2.3.6 (page 14) in which this is described and the recommended layout is on page 16, Figure 16)

    you can characterize this and see if it matters or not - it was a dramatic lag, but it was noticeable enough that it seems relevant to share this with you. 

    Hope that helps you out. 

    BR-

    Josh

This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.