About Pd and Tj

ACGUY

Hi all,

I have questions about logic devices, SN74AHC1G32DCKR and SN74LVC244ARGYR.

1. Please let me know their absolute maximum Pd (Allowable power dissipation).
2. Please let me know their recomended maximum Tj in 25℃ ambient .

Regards,
Nagai

over 9 years ago

0 ShreyasRao over 9 years ago

TI__Guru 62160 points

Hi Nagai san ,

The datasheet only specifies the abs max Tj which is 150C . The operating Tj can be estimated by the Tj = Ta + Pd*thetaJA . where Pd is the power dissipation and Ta is the ambient temp .

0 ShreyasRao over 9 years ago in reply to ShreyasRao

TI__Guru 62160 points

The Pd is a combination of Pstatic and Pdynamic , where Pstatic is Vcc * Icc and dynamic component depends on the switching frequency ,load capacitance , power dissipation capacitor .
The app note explains the calculation of power dissipation in CMOS logic circuits .
www.ti.com/.../scaa035b.pdf

0 ACGUY over 9 years ago in reply to ShreyasRao

Guru 11170 points

Hello Shreyas-san,

Thank you for answer.
I really appreciate your help in resolving the problem.

Thanks,
Nagai

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About Pd and Tj