AMD 8 --- I-- high------ , T die , spec + 273.15 ⋅ ln, cancellation, = T die , spec + 273.15 ⋅

Preliminary Information

25175H —March 2003 AMD Athlon™ XP Processor Model 8 Data Sheet

The formulas in Equation (3) and Equation (4) can be used to calculate the temperature offset for temperature sensors that do not employ series resistance cancellation. The result is added to the value measured by the temperature sensor. Contact the vendor of the temperature sensor being used for

the value of nf,TS. Refer to the document, On-Die Thermal Diode Characterization, order# 25443, for further details.

Equation (3) shows the equation for calculating the lumped

ideality factor (nf, lumped) in sensors that do not employ series resistance cancellation.

nf, lumped = nf, actual + ----	RT ⋅ (Ihigh – Ilow )			(3)
	-----------------------------------------------------	---I--high--------
k	(Tdie, spec + 273.15) ⋅ ln
--		 -I--low----	
q

Equation (4) shows the equation for calculating temperature offset (Toffset) in sensors that do not employ series resistance

cancellation.
T	= (Tdie, spec + 273.15) ⋅		1 – --------------		(4)
			nf, lumped
o f f s e t			nf, TS	

Equation (5) is the temperature offset for temperature sensors that utilize series resistance cancellation. Add the result to the value measured by the temperature sensor. Note that the value

of nf,TS in Equation (5) may not equal the value used in Equation (4).

		nf, actual
To f f s e t = (Tdie, spec + 273.15) ⋅ 	1 –	----n---f-,-TS------	(5)

Appendix A - Thermal Diode Calculations 85