Intel U2400 LE80539UE0042M User Manual

86

Datasheet

NOTES:
1.

Intel does not support or recommend operation of the thermal diode under reverse bias. 
Intel does not support or recommend operation of the thermal diode when the processor 
power supplies are not within their specified tolerance range.

2.

Characterized across a temperature range of 50 - 100°C.

3.

Not 100% tested. Specified by design characterization.

4.

The ideality factor, n, represents the deviation from ideal diode behavior as exemplified by 
the diode equation:

I

FW

 = I

S

 * (e 

qV

D

/nkT

 –1)

where I

S

 = saturation current, q = electronic charge, V

D

 = voltage across the diode, k = 

Boltzmann Constant, and T = absolute temperature (Kelvin).

5.

The series resistance, R

T

, is provided to allow for a more accurate measurement of the 

junction temperature. R

T

, as defined, includes the lands of the processor but does not 

include any socket resistance or board trace resistance between the socket and the 
external remote diode thermal sensor. R

T

 can be used by remote diode thermal sensors 

with automatic series resistance cancellation to calibrate out this error term. Another 
application is that a temperature offset can be manually calculated and programmed into 
an offset register in the remote diode thermal sensors as exemplified by the equation:

T

error

 = [R

T

 * (N-1) * I

FWmin

] / [nk/q * ln N]

where T

error

 = sensor temperature error, N = sensor current ratio, k = Boltzmann 

Constant, q = electronic charge. 

NOTES:
1.

Intel does not support or recommend operation of the thermal diode under reverse bias.

2.

Same as I

FW 

3.

Characterized across a temperature range of 50 - 100°C.

4.

Not 100% tested. Specified by design characterization.

5.

The ideality factor, nQ, represents the deviation from ideal transistor model behavior as 
exemplified by the equation for the collector current:

I

C

 = I

S

 * (e 

qV

BE

/n

Q

kT

 –1)

Where I

S

 = saturation current, q = electronic charge, V

BE

 = voltage across the transistor 

base emitter junction (same nodes as VD), k = Boltzmann Constant, and T = absolute 

temperature (Kelvin).

6.

The series resistance, R

T,

 provided in the Diode Model Table (

) can be used for 

more accurate readings as needed. 

I

FW

Forward Bias Current

5

-

200

µA

1

n

Diode Ideality Factor

1.000

1.009

1.050

-

2, 3, 4

R

T

Series Resistance

2.79

4.52

6.24

Ω

2, 3, 5

I

FW

Forward Bias Current

5

-

200

µA

1, 2

I

E

Emitter Current

5

200

µA

n

Q

Transistor Ideality

0.997

1.001

1.005

-

3, 4, 5

Beta

0.3

0.760

3, 4

R

T

Series Resistance

2.79

4.52

6.24

Ω

3, 6