Tool/software:
Dear Sir/Madam,
Thank you for your help.
I have two questions regarding the Thermal Information of the TPS62140:
1.
Since I have been using this product continuously since fiscal year 2012,
I have two versions of the datasheet.
The thermal resistance values listed in the datasheets—one copyrighted © 2011
and the other © 2011–2016—differ significantly.
Is it correct to assume that this difference is due to variations
in measurement methods (the © 2011–2016 version complies with JESD51-2)?
Although the numerical values differ,
are the package characteristics considered equivalent?
Datasheet excerpt (TPS6214X RGT (16) PINS):
© 2011 version:
θJA = 29.1°C/W
θJC(TOP) = 15°C/W
θJB = 11°C/W
ψJT = 0.5°C/W
ψJB = 10°C/W
θJC(BOTTOM) = 3.5°C/W
© 2011–2016 version:
RθJA = 45°C/W
RθJC(top) = 53.6°C/W
RθJB = 17.4°C/W
ψJT = 1.1°C/W
ψJB = 17.4°C/W
RθJC(bot) = 4.5°C/W
2.
Regarding the calculation formulas for junction
temperature mentioned above, is the following approach correct?
Evaluation Conditions:
・No heatsink
・Case temperature (Tc) measured with a thermocouple
© 2011 version:
TJ = TC + (θJC(TOP) × Power)
© 2011–2016 version:
TJ = TC + (ΨJT × Power)
Thank you very much for your assistance.
Best regards,
Yoshiyuki Otaki
