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How to estimate/calculate the power dissapation as a function of the chip temperature

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Bjarredsbon

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If someone knows how to estimate/calculate the power dissapation as a function of the chip temperature, please send a reply or an email.

Thank you.
 

phutanesv

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Re: Power vs Temperature

Dear Dude,

Normally power analaysis will be done for power.

actually what is ur question in could not get properly.

r u saying about dynamic power or vdd or vss.

which power r u taking about.

phutane
 

Bjarredsbon

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Re: Power vs Temperature

If the chip was a true resistor, the power would decrease as the resistance increases with temperature (P=U*I, I=U/R, P=U*U/R)

But transistors are more complex beasts, with many parameters changing with temperature (I suppose).

Previsouly I have used a rule of thumb, 10% more power when going from 90C to 125C, but I am no longer sure this is true.

Any facts?

Thanks.
 

phutanesv

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Re: Power vs Temperature

Dear Bjarredsbon


Temperture affects many parameter like

mobility decreases, β decreases

due to this Current Ids decreases

salso there will be small change in Vt, which depends on substrate doping

a variation of -3degreev/centigrade will be there.

means for a 80 degree rise in temperature there will 30% decrease in transistor

gain and a drop about 240mV in Vt.

one more speed also decreases.

phutane
 

ubna

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Re: Power vs Temperature

The temperature of a chip depends upon the power dissipated per unit area of the chip....
 

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