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OPA552: This opamp appears run very hot with resistive load.

Doug Smyth
Prodigy 220 points
Part Number: OPA552

I have the OPA552 opamp in a circuit with a gain of ~6.5. I dropped the resistor values and now I have a clean signal. I have two of these in a circuit and one is used as a simple  40v switch for DC current. Both are driving resistor loads(currently 10Kohm). Both of these opamps are hot to the touch (~80C). I now have a stick-on heatsink. Is it normal for this component to run hot?

  • 0
    Guru 140200 points
    Hi Doug,

    can you show a schematic?

    Kai
  • 0
    TI__Guru* 93105 points

    Hi Doug,

    You don't mention the OPA552 package type you are using, but for a given power situation the SOIC will get much hotter than DDPAK. The quiescent power with +/-30 V supplies results in about 0.42 W dissipation which can cause the very small package to heat up. Having the schematic as Kai suggests would help us better visualize you application and help understand the power implications.

    Do check the output of the OPA552 Op amps and make sure there isn't any high-frequency oscillation present. If by chance there is oscillation, then that could result in excessive power dissipation.

    Regards, Thomas

    Precision Amplifiers Applications Engineering

  • 0 in reply to Thomas Kuehl
    Prodigy 220 points
    I will try to get a schematic. It is an SOIC package and 1/2 watt does seem like a lot for that component. Let me do some math... It is about 4 of these per cm squared. ...2 watts. That would yield a 10cm x 10cm at 200 watts. That is a lot. The next generation PCB will have mounting holes about all SOIC opamps for heatsinks. Also, the touch test can be misleading as my finger insulates half the heat dissipation. Just checked, the output looks steady.