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TMP110: PCB Layout - and Alternate part

RAJESH Kumar
Prodigy 50 points

Part Number: TMP110
Other Parts Discussed in Thread: TMP1075

Hi,

Currently, we have considered TMP110D0IDPWR in using proto development in a application which runs on loop powered device. For evaluation, we had used the EVM kit and completed the functional validation. This part meets our current consumption requirement and now we are planning to incorporate this sensor in our PCB. During PCB design phase, we are facing few challenges mainly due to DFM constraints - PCB fabricator require min 5mils tolerance between pad to pad on a copper thickness of 2 oz/70microns finished thickness. We can't reduce the cu thickness as this is a 2 layer PCB designed for thermal dissipation.

  1. Can we remove this 0.1mm via in pad#3. We are connecting this pin directly to GND pad, as we do not intend to use ALERT functionality. Do you see any reliability issue if we don't use this via?
  2. Alternatively, can we leave this pin floating, as we don't use the Alert functionality.
  3. In the below example land pattern - typ exposed metal clearance is only 0.21mm. Can we consider the same value with respect to all the pads, please confirm.
  4. Alternatively, we are thinking to go with other equivalent part, for example - TMP1075DSGR. Could you please check on the peak current consumption of this part and confirm the specs are similar to the TMP110 series parts. 

image.png

Please let me know if you require more details to clarify the above.

 

Best Regards,

Rajesh

 

  • +1
    TI__Intellectual 2305 points

    Hello Rajesh,

    Yes, it is fine to both ground the middle pin or leave it floating if you are not using ALERT.

    The typical exposed metal clearance should apply to all the pads.

    The TMP110 and TMP1075 have very similar peak current consumptions and have similar other specs. The TMP1075 has more I2C options but has slightly worse accuracy at the extreme temperatures compared to the TMP110. They have slightly different temperature ranges and voltage supply ranges. There are also have some minor software differences, namely the configuration register layout.

    Let me know if there are further questions! Thanks,

    Hypatia

  • 0
    Prodigy 50 points

    Hello Hypatia,

    Thanks a lot for clarifications. We have updated the PCB design and shared to the fabricator. Let's wait and see if it is ok.

    Best Regards,

    Rajesh