------Question for SN74AVC4T774RGYR Please Put your question below------
Hi, does the exposed central pad require a connection to GND or should it be left floating?
Regards
Thomas
Hi Steven,
I searched and read the datasheet thoroughly before asking, including the related document hinted on page 32 of the datasheet.
“This package is designed to be soldered to a thermal pad on the board. For more information, see Texas Instruments literature
number SLUA271 (www.ti.com/lit/slua271) .”
The assurance I need is not in the datasheet and for me it is not OK, to not use this PCB real state, to connect surrounding pins.
That I conclude from the datasheet that it has to be left floating and only used for thermal purposes, only because the document is not explicit about it, is only guessing.
On datasheets (most of them) the thermal requirements and voltage restrictions of an Exposed Pad are treated as separate attributes in explicit ways.
Like it is mandatory that it be soldered on the board, that eventually thermal vias are used in a certain pattern, depending of the layer count of the PCB etc.
Likewise, regarding voltages, some indicate it to be left floating, to be tied to VDD or to be tied to GND.
I will try with TI, but yesterday the support site was on maintenance when I was dealing with this issue.
Will try with them again today.
Thanks,
Thomas
Hello @tmagdahl,
There is no electrical requirement to solder the pad. However, a proper heatsink (e.g., thermal via) will improve thermal properties.
We can expand the search to related components from other OEMs. For example, a related Nexperia datasheet claims:
In case soldered, the solder land should remain floating or connected to GND.
Also, I did find a TI application note that states:
The thermal pad is usually tied to ground, and designers should verify the electrical
correctness when connecting the copper planes to the thermal pad.
Please let us know what TI has to say.
Happy soldering,
APDahlen