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TPS22933: TPS22933 Operation temperature question

Part Number: TPS22933

Hi Folks ,

 i have one question regarding the operting temperture of this part .

I want to use this Part at a PCB which will be operated up to 120°C Board Temperature with an Air Tempertur flowing around the PArts with up to 70 °C Ambient.

Is it possible to use this part at my PCB without damagin it ? Because the Datasheet only states the free air temperture operating range of -40 ° C to 85°C , the junction temperture is higher i guess ?

Thank and greetings

  • Hi Hergen,

    If my understanding is correct, then you want to use this device with a board temperature of 120°C and an ambient air temperature of 70°C. As you mentioned, the junction temperature range is not listed for this device, but it is higher than the ambient air temperature. Can you give me an idea of how much current you are passing through the device and what input voltages you are using? That way I can take a look at power dissipation and expected temperature rise in the device.

    Thanks,

    Alek Kaknevicius

  • Hi Alek,

    thanks for your reply on this topic.

    Your understanding is correct on the use of this part. The current flowing through the divice is jst only a few mAmps which are dissipated through a microcontroller, which shall work with 2 different voltages if one of the voltages fails.

    The Heatgeneration of the PCB comes from other parts on the PCB and not through the multiplexer itself.

    Greetings
  • Hi Hergen,

    Doing some calculations, it looks like the self heating for the device would be minor even for max loads. Taking a look at the history of the device, it looks like all of our testing and design was based on a temperature of 85C, so we do not have any extensive testing for the device at higher temperatures. Therefore, we cannot guarantee the performance or operation of the device at the higher temperature of 120C, only the 85C that is in the datasheet.

    That's not to say that the device will not work, only that we cannot make any guarantees since we do not have the data to support a higher junction temperature.

    Thanks,

    Alek Kaknevicius