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AD820 Junction temperature


Could you  teach me about the junction temperature of AD820 because AD820 datasheet does not describe the junction ?

I think that the junction temperature is 150 degree celcius  as other parts and is it correct ?

Datasheet describes the internal power dissipation at absolute maximum rate.

These are  below and I think that these are defined at 0 degree celcius.

But, maximum junction temperature is 160 degree celicus at SOIC.   ( 1.0W  *160 degree celcius/W) .

So please let me cralify the junction temeprature of AD820.

Internal Power Dissipation at datasheet
8-Lead PDIP (N) 1.6 W
8-Lead SOIC_N (R) 1.0 W
8-Lead MSOP (RM) 0.8 W



  • Hi Terumasa,

    In computing for the junction temperature of a device you can use the formula: 

    Power dissipation is given by the formula:

    Assuming quiescent condition and no load is connected, junction temperature of your device at room temp. are:

    PD @ Vsy = +/-15V, Isy = 900uA
    PD = 27mW

    TJ(PDIP) = 25C + (90 C/W x 27mW)

                   = 27.43C

    TJ(SOIC) = 25C + (160 C/W x 27mW)

                    = 29.32C

    TJ(MSOP) = 25C + (190 C/W x 27mW)

                   = 30.13C

    If you want to learn more about absolute maximum ratings and thermal resistances you can refer to this Technical Article.


  • Hi Terumasa,

    Junction temperature range is limited to -65C to 150C to avoid violating the absolute maximum ratings. The formulas above can help you in calculating whether you are operating within the range.

    May I know why you needed the information?


  • Helloi Gauzz,

    Thank you for your reply.

    Could you teach me about the maximum junction temperature of AD820  ?

    This is not described in the datasheet.

    Alomost all of parts is desribed as 150 degree celcius but AD820 is not descibed.

    So ,  our customer asks maximum junction temperature of AD820.

    Please let me know your advice.



  • Hello Goz,

    Thank you for your answer.