Intel® Quiet System Technology (Intel® QST)
Thermal and Mechanical Design Guidelines
65
temperature to the target temperature. As a result of its operation, the PID control
algorithm can enable an acoustic-friendly platform.
Figure 7-2. PID Controller Fundamentals
For a PID algorithm to work limit temperatures are assigned for each temperature
sensor. For Intel QST, the T
CONTROL
for the processor and chipset are to be used as the
limit temperature. The ME will measure the error, slope and rate of change using the
equations below:
•
Proportional Error (P) = T
LIMIT
– T
ACTUAL
•
Integral (I) = Time averaged error
•
Derivative (D) = ΔTemp / ΔTime
Three gain values are used to control response of algorithm.
•
Kp = proportional gain
•
Ki = Integral gain
•
Kd = derivative gain
The
Intel
®
Quiet System Technology (Intel
®
QST) Configuration and Tuning Manual
provides initial values for the each of the gain constants. In addition it provides a
methodology to tune these gain values based on system response.
Finally, the fan speed change will be calculated using the following formula:
ΔPWM = -P*(Kp) – I*(Ki) + D*(Kd)
Proportional
Error
Derivative (Slope)
Integral (time averaged)
Proportional
Error
Derivative (Slope)
Integral (time averaged)
Proportional
Error
Derivative (Slope)
Integral (time averaged)
Proportional
Error
Derivative (Slope)
Integral (time averaged)
R
PM
Te
m
pe
ra
tur
e
Time
+
dP
W
M
+
dP
W
M
+
dP
W
M
+
dP
W
M
+
dP
W
M
+
dP
W
M
-
-
dP
W
M
dP
W
M
-
-
dP
W
M
dP
W
M
-
-
dP
W
M
dP
W
M
Actual
Temperature
Actual
Temperature
Fan
Speed
Fan
Speed
Limit
Temperature
Limit
Temperature
Summary of Contents for CELERON PROCESSOR E3000 - THERMAL AND MECHANICAL DESIGN
Page 24: ...Processor Thermal Mechanical Information 24 Thermal and Mechanical Design Guidelines ...
Page 80: ...Heatsink Clip Load Metrology 80 Thermal and Mechanical Design Guidelines ...
Page 82: ...Thermal Interface Management 82 Thermal and Mechanical Design Guidelines ...
Page 108: ...Fan Performance for Reference Design 108 Thermal and Mechanical Design Guidelines ...