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.

OPA2211A Thermal performance?

Other Parts Discussed in Thread: OPA2211A

I've got a question about the OPA2211A.  We're using this on a design and I noticed that we've connected the Thermal pad underneath the part to GND.  In the datasheet it says we should connect it to the Negative voltage which in our case is -5V.  This board is operational in the lab, so nothing catastrophic has happened, but I am concerned about the thermal performance and how far we may be off the specs.  Can TI give us an idea of how bad this might be?  Is this something we must change?  I know you can't tell us too much given everything is application specific, but I'm just looking for a ball park estimate of what we might expect.

  • James,

    The exposed leadframe die pad on the bottom of the package MUST be connected to negative supply.  Since the substrate of the OPA2211 is internally biased at the negative supply, connecting thermal pad to any other potential will create a differential voltage across the back-side of the die that may capacitively couple into the IC substrate, which in turn may diminish its AC performance.  Since OPA2211 has never been characterized under such conditions, it is impossible to say how various specs might be effected by connecting thermal pad to mid-supply (GND in your case).