Home » Intel Manuals » Processors » Intel 640 » Manual Viewer

Intel 640 User Guide - Page 87

Appendix E Board Level PWM and Fan, Speed Control, Requirements

UPC - 683728178901

Add to My Manuals
Save this manual to your list of manuals

Page 87 highlights

Board Level PWM and Fan Speed Control Requirements R Appendix E Board Level PWM and Fan Speed Control Requirements To use all of the features in the Intel reference heatsink design or the Boxed Intel Pentium 4 Processor in 775-land LGA package, system integrators should verify the following functionality is present in the board design. Refer to the Fan Specification for 4 wire PWM Controlled Fans and Chapter 5 for complete details on the Intel enabled thermal solution. The basics of Fan Speed Control are discussed in Chapter 6; as a review, the FSC definitions are listed in Table 7. Table 7. FSC Definitions Item TDIODE TCONTROL TLOW Hysteresis THIGH All Fans ON Min PWM Spin-up PWM Freq TAVERAGING Definition Temperature reported from the processor on-die thermal diode. TCONTROL is the specification limit for use with the on-die thermal diode The temperature above which the fan will begin to accelerate in response to the on-die thermal diode temperature. The number of degrees below T-control the fans will remain on before slowing down. The temperature at which the fan is operating at full speed (100% PWM Duty Cycle). By specification this is TCONTROL. The processor temperature at which all fans in the system are increased to 100% Duty Cycle. Minimum pulse width modulation (% duty cycle) that the fans will run at when TDIODE is less than TLOW. Amount of time fan is run at 100% duty cycle to overcome fan inertia. The operating frequency of the PWM signal. The time (in seconds) that elapses while the fan is gradually sped up in response to a processor temperature spike. Thermal/Mechanical Design Guide 87

Section	Page
Contents	3
Figures	6
Tables	7
Revision History	8
1 Introduction	9
1.1 Document Goals and Scope	9
1.1.1 Importance of Thermal Management	9
1.1.2 Document Goals	9
1.1.3 Document Scope	10
1.2 References	11
1.3 Definition of Terms	12
2 Processor Thermal/Mechanical Information	15
2.1 Mechanical Requirements	15
2.1.1 Processor Package	15
2.1.2 Heatsink Attach	17
2.1.2.1 General Guidelines	17
2.1.2.2 Heatsink Clip Load Requirement	17
2.1.2.3 Additional Guidelines	18
2.2 Thermal Requirements	18
2.2.1 Processor Case Temperature	18
2.2.2 Thermal Profile	19
2.2.3 TCONTROL	20
2.3 Heatsink Design Considerations	21
2.3.1 Heatsink Size	22
2.3.2 Heatsink Mass	22
2.3.3 Package IHS Flatness	22
2.3.4 Thermal Interface Material	23
2.4 System Thermal Solution Considerations	23
2.4.1 Chassis Thermal Design Capabilities	23
2.4.2 Improving Chassis Thermal Performance	23
2.4.3 Summary	24
2.5 System Integration Considerations	24
3 Thermal Metrology	25
3.1 Characterizing Cooling Performance Requirements	25
3.1.1 Example	26
3.2 Processor Thermal Solution Performance Assessment	27
3.3 Local Ambient Temperature Measurement Guidelines	27
3.4 Processor Case Temperature Measurement Guidelines	30
4 Thermal Management Logic and Thermal Monitor Feature	31
4.1 Processor Power Dissipation	31
4.2 Thermal Monitor Implementation	31
4.2.1 PROCHOT# Signal	32
4.2.2 Thermal Control Circuit	32
4.2.3 Operation and Configuration	33
4.2.4 On-Demand Mode	34
4.2.5 System Considerations	34
4.2.6 Operating System and Application Software Considerations	35
4.2.7 On-Die Thermal Diode	35
4.2.7.1 Reading the On-Die Thermal Diode Interface	35
4.2.7.2 Correction Factors for the On-Die Thermal Diode	36
4.2.8 THERMTRIP# Signal	37
4.2.8.1 Cooling System Failure Warning	37
5 Intel® Thermal/Mechanical Reference Design Information	39
5.1 Intel Validation Criteria for the Reference Design	39
5.1.1 Heatsink Performance Target	39
5.1.2 Acoustics	40
5.1.3 Altitude	40
5.1.4 Reference Heatsink Thermal Validation	41
5.1.5 Fan Performance for Active Heatsink Thermal Solution	41
5.2 Environmental Reliability Testing	42
5.2.1 Structural Reliability Testing	42
5.2.1.1 Random Vibration Test Procedure	42
5.2.1.2 Shock Test Procedure	42
5.2.2 Power Cycling	44
5.2.3 Recommended BIOS/Processor/Memory Test Procedures	44
5.3 Material and Recycling Requirements	44
5.4 Safety Requirements	45
5.5 Geometric Envelope for ATX Intel® Reference Thermal Mechanical Design	45
5.6 ATX Reference Thermal Mechanical Solution for the Intel® Pentium® 4 Processor in the 775–Land LGA Package	46
5.7 Reference Attach Mechanism	48
5.7.1 Structural Design Strategy	48
5.7.2 Mechanical Interface to the Reference Attach Mechanism	49
6 Acoustic Fan Speed Control	53
6.1 Acoustic Fan Speed Control	53
6.2 Thermal Solution Design	53
6.2.1 Compliance to Thermal Profile	53
6.2.2 Determine Thermistor Set Points	53
6.2.3 Minimum Fan Speed Set Point	54
6.3 Board and System Implementation	55
6.3.1 Choosing Fan Speed Control Settings	55
6.3.1.1 Temperature to begin Fan Acceleration	56
6.3.1.2 Minimum PWM Duty Cycle	58
6.4 Combining Thermistor and Thermal Diode Control	59