Intel® Quiet System Technology (Intel® QST)
Thermal and Mechanical Design Guidelines
67
target temperature. As a result of its operation, the PID control algorithm can enable
an acoustic-friendly platform.
Figure
7-2. PID Controller Fundamentals
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)
RPM
Tempera
ture
Time
+ dPW
M
+ d
PW
M
+ dPW
M
+ d
PW
M
+ dPW
M
+ d
PW
M
-
-
dP
WM
dP
WM
-
-
dP
WM
dP
WM
-
-
dP
WM
dP
WM
Actual
Temperature
Actual
Temperature
Fan
Speed
Fan
Speed
Limit
Temperature
Limit
Temperature
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) =
Δ
Temp /
Δ
Time
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:
Δ
PWM = -P*(Kp) – I*(Ki) + D*(Kd)
Summary of Contents for BX80570E8200 - Core 2 Duo 2.66 GHz Processor
Page 10: ...10 Thermal and Mechanical Design Guidelines...
Page 26: ...Processor Thermal Mechanical Information 26 Thermal and Mechanical Design Guidelines...
Page 82: ...Heatsink Clip Load Metrology 82 Thermal and Mechanical Design Guidelines...
Page 84: ...Thermal Interface Management 84 Thermal and Mechanical Design Guidelines...
Page 110: ...Fan Performance for Reference Design 110 Thermal and Mechanical Design Guidelines...