TCA9517: Tj and Pd for TCA9517DGKR

Eng,

An engineer has been notified of this thread and will respond by tomorrow, July 6th. Thank you for your patience.

Regards,

Eric Hackett 

Eng,

After reading this again, can you clarify what exactly is needed here? I understand you want to know the junction temperature and power dissipation, but these aren't parameters that can be extracted just from knowing the thermal resistance. 

Also, the DGK package numbers are slightly different, that's a mistake on my last post. Tjc = 59.3 and Tja = 187.6

Regards,

Eric Hackett

Hi Eric,

I intend to get the Case Temperature, Tc as below:

In actual system level measurement, we could measure the Tc.

Then only we will direct compare Tc_measured with the Tc_spec.

As Tjc already provided by you, we would need Tj & Pd spec

Thanks

Eng,

Thanks for sharing these formulas. The Pd number will be the power dissipated in the circuit, which isn't something I can give unless I know the conditions of the application. For Tj we could limit it to the maximum allowable junction temperature of the device, or it can be found using the formula Kenneth provided, but you'd again need to know the power dissipated and the ambient temperature of the application. 

These parameters will be specific to how the device is being used, and not something that is necessarily spec'd or independent.

Regards,

Eric Hackett 

Hi Eric,

Thank you so much for the explanation.

We will measure the Pd as per our application

However, is it possible to share the max allowance for junction temperature, Tjmax?

Thank you!

Eng,

For this device I believe it is 105C. The maximum ambient temperature is 85C, and typically the maximum junction temperature is just above that.

That being said, the device will not be damaged until 150C. The 105C is what the device will work within the datasheet limits under.

Regards,

Eric Hackett