Sensor Based Thermal Specification Design Guidance

Figure 8-3. DTS 1.1 Definition Points

Table 8-1. DTS 1.1 Thermal Solution Performance above TCONTROL

 

ψCA at

ψCA at

ψCA at

ψCA at

Processor TDP

DTS = -1 At

DTS = -1 At

DTS = -1 At

DTS =

System

System

System

 

TCONTROL1,2

ambient_max=

ambient_max=

ambient_max=

 

 

40C

45C

50C

 

 

 

 

 

95W(no graphic)

0.569

0.354

0.300

0.248

 

 

 

 

 

95W(with graphic)

0.564

0.343

0.291

0.238

 

 

 

 

 

80W (no graphic)

0.620

0.364

0.300

0.238

 

 

 

 

 

45W(with graphic)

0.869

0.413

0.301

0.191

 

 

 

 

 

20W(no graphic)

3.713

1.875

1.625

1.375

 

 

 

 

 

Notes:

1.ΨCA at “DTS = Tcontrol” is applicable to systems that has Internal Trise (Troom temperature to Processor cooling fan inlet) of less than 10 °C. In case your expected Trise is grater than 10 °C a correction factor should be used as explained below. For each 1 °C Trise above 10 °C, the correction factor CF is defined as CF= 1.7 / Processor_TDP.

2.Example, For A Chassis Trise assumption of 12 °C for a 95W TDP processor. CF = 1.7/95 W = 0.018/C

For Trise > 10 C

ΨCA at Tcontrol = Value listed in Column_2 - (Trise - 10) * CF ΨCA = 0564 - (12 - 10) * 0.018 =0.528 C/W

In this case the fan speed should be set slightly higher equivalent to YCA=0.528C/W

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Thermal/Mechanical Specifications and Design Guidelines