MSP430F5341IRGZ thermal pad

rodtalicc said:

I am working on a design using MSP430F5341IRGZ and I want to make sure that I terminate the thermal pad on the QFN package correctly. Is this pad to be grounded to the ground plane through vias or should the pad be left floating?

The data sheet is not clear enogh to give an answer, so I have asked for this to be updated.

I also checked some other MSP430 devices that share the same 48VQFN (RGZ) package:

MSP430F5510
MSP430F5310
MSP430FG4270

In each case, the data sheet recommends that the power pad (QFN pad) be connected to
Vss (ground).

This is actually a problem in many TI datasheets using QFN with thermal PAD. The generic datasheet of the package says to connect the pad to a GND or power plane as recommended in the datasheet. But the datasheet itself, almost always, omits to tell the connection of the thermal PAD.

If you make a search through the forums, you will see this question popping many times for many devices with thermal pad.

A simple multimeter will tell you whether the thermal pad and the VSS/GND pin are directly connected. If so, do it. If not, don't. I bet it is. :)

Generally, if the generic document tells you a fact, there's no reason to repeat it in the more detailed documents. HTat's why there is a generic document. Else it could/would be included as a whole in the specific documents.

The generic document DOESNT tell you to connect to GND. It only tells you to connect it to a power plane (GND OR VCC) according what the datasheet says. And then the datasheet says nothing

Albert_83 said:

It only tells you to connect it to a power plane (GND OR VCC)

However, the multimeter suggeston still jholds. If it needs to be tied to VCC, there will be a noticeable resistance (semiconductor-induced voltage drop) between the pad and any GND pin. If there is a clean shortcut, then it needs to be tied to GND. The generic document excludes any other neccessity (like leaving it floating).

And you're right, the datasheet then should say something. But even though it doesn't, it's not difficult to figure out yourself. Faster than writing a quesiton in the forum.

Can you please confirm the proper termination for the thermal pad? Unfortunately, I cant verify the suggestion that Jens-Michael  gave of doing a multimeter test on the part because I am traveling and I dont have access to the part or a multimeter to carry out the test. Please help me confirm this so I can finalize my design for prototyping. 

rodtalicc said:

Is this pad to be grounded to the ground plane through vias or should the pad be left floating?

You are recommended to connect the thermal pad to Vss for the MSP430F5341IRGZ.  The data sheet has been updated to reflect this.