Intel 520J Data Sheet - Page 83

Datasheet

83

Thermal Specifications and Design Considerations

5.2.7

Thermal Diode

The processor incorporates an on-die thermal diode. A thermal sensor located on the system board

may monitor the die temperature of the processor for thermal management/long term die

temperature change purposes.

Table 5-4

and

Table 5-5

provide the diode parameter and interface

specifications. This thermal diode is separate from the Thermal Monitor’s thermal sensor and

cannot be used to predict the behavior of the Thermal Monitor.

§

Table 5-4. Thermal Diode Parameters

Symbol

Parameter

Min

Typ

Max

Unit

Notes

I

FW

Forward Bias Current

11

187

μA

1

NOTES:

1.

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

n

Diode Ideality Factor

1.0083

1.011

1.023

2, 3, 4, 5

2.

Characterized at 75 °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.

Devices found to have an ideality factor of 1.0183 to 1.023 will create a temperature error approximately 2 C° higher than

the actual temperature. To minimize any potential acoustic impact of this temperature error, T

CONTROL

will be increased by

2 C° on these parts.

R

T

Series Resistance

3.242

3.33

3.594

Ω

2, 3, 6

6.

The series resistance, R

T

, is provided to allow for a more accurate measurement of the thermal diode temperature. R

T

, as

defined, includes the pins of the processor but does not include any socket resistance or board trace resistance between

the socket and the external remote diode thermal sensor. RT 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 manu-

ally 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.

Table 5-5. Thermal Diode Interface

Signal Name

Land Number

Signal Description

THERMDA

AL1

diode anode

THERMDC

AK1

diode cathode

Section	Page
Contents	3
Revision History	7
Intel® Pentium® 4 Processors 570/571, 560/561, 550/551, 540/541, 530/531, and 520/521	9
1 Introduction	11
1.1 Terminology	12
1.1.1 Processor Packaging Terminology	12
1.2 References	13
2 Electrical Specifications	15
2.1 FSB and GTLREF	15
2.2 Power and Ground Lands	15
2.3 Decoupling Guidelines	15
2.3.1 VCC Decoupling	16
2.3.2 FSB GTL+ Decoupling	16
2.3.3 FSB Clock (BCLK[1:0]) and Processor Clocking	16
2.4 Voltage Identification	17
2.4.1 Phase Lock Loop (PLL) Power and Filter	19
2.5 Reserved, Unused, FC and TESTHI Signals	20
2.6 FSB Signal Groups	21
2.7 GTL+ Asynchronous Signals	22
2.8 Test Access Port (TAP) Connection	23
2.9 FSB Frequency Select Signals (BSEL[2:0])	23
2.10 Absolute Maximum and Minimum Ratings	24
2.11 Processor DC Specifications	24
2.12 VCC Overshoot Specification	33
2.12.1 Die Voltage Validation	33
2.13 GTL+ FSB Specifications	34
3 Package Mechanical Specifications	35
3.1 Package Mechanical Drawing	35
3.2 Processor Component Keep-Out Zones	39
3.3 Package Loading Specifications	39
3.4 Package Handling Guidelines	39
3.5 Package Insertion Specifications	40
3.6 Processor Mass Specification	40
3.7 Processor Materials	40
3.8 Processor Markings	40
3.9 Processor Land Coordinates	41
4 Land Listing and Signal Descriptions	43
4.1 Processor Land Assignments	43
4.2 Alphabetical Signals Reference	66
5 Thermal Specifications and Design Considerations	75
5.1 Processor Thermal Specifications	75
5.1.1 Thermal Specifications	75
5.1.2 Thermal Metrology	79
5.2 Processor Thermal Features	79
5.2.1 Thermal Monitor	79
5.2.2 Thermal Monitor 2	80
5.2.3 On-Demand Mode	81
5.2.4 PROCHOT# Signal	82
5.2.5 THERMTRIP# Signal	82
5.2.6 TCONTROL and Fan Speed Reduction	82
5.2.7 Thermal Diode	83
6 Features	85
6.1 Power-On Configuration Options	85
6.2 Clock Control and Low Power States	85
6.2.1 Normal State	86
6.2.2 HALT and Enhanced HALT Powerdown States	86
6.2.2.1 HALT Powerdown State	86
6.2.2.2 Enhanced HALT Powerdown State	86
6.2.3 Stop-Grant State	87
6.2.4 Enhanced HALT Snoop or HALT Snoop State, Grant Snoop State	88
6.2.4.1 HALT Snoop State, Grant Snoop State	88
6.2.4.2 Enhanced HALT Snoop State	88
7 Boxed Processor Specifications	89
7.1 Mechanical Specifications	90
7.1.1 Boxed Processor Cooling Solution Dimensions	90
7.1.2 Boxed Processor Fan Heatsink Weight	91
7.1.3 Boxed Processor Retention Mechanism and Heatsink Attach Clip Assembly	91
7.2 Electrical Requirements	91
7.2.1 Fan Heatsink Power Supply	91
7.3 Thermal Specifications	93
7.3.1 Boxed Processor Cooling Requirements	93

Intel 520J Data Sheet - Page 83

Thermal Diode

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