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OPA548: Wrong/missing thermal specifications in datasheet (revision C & D)

Part Number: OPA548


we are using a OPA548F in the automotive sector for impedance measurement excitation.

Actual we recogized, that the amplifier thermal shuts down in some enviromental conditions.

After research we recognized a conflict in the datasheet (Revision D). 
On Page 4 - "Thermal Information" RthJC(bot) is specified with 0,2 K/W equal for both packages.
On Page 28 - " Heat Sink Selection Example" a value of 2,5 k/W is mentioned (TO-220)?

For optimal thermal design it would be nice to get the right values. 

Is there any aplication note with this specifications?

Best regards,


  • Hi Erik,

    Is there any aplication note with this specifications?

    The junction to case thermal resistance on bottom is rated at 0.2C/W and this figure should be used in the calculation below. The thermal figure is simulated via the thermal model based on the package and die information. This is done by our thermal modeling team based on the JEDEC standard (package thermal pad surface mounted type including thermal vias).   

    The calculation in Section had a typo. Please see the revised overall thermal resistance per the estimation. 

    BTW, OPA548F is not automotive grade power amplifier. The automotive grade (AEC-Q100 qualification) should have -Q1 designated at the end of the part number.  

    If you have other questions, please let us know.