Altera PowerPlay Early Power Estimator - Manual (Page 20)

3–2 Altera Corporation
PowerPlay Early Power Estimator For Stratix II, Stratix II GX & HardCopy II January 2007
PowerPlay Early Power Estimator Inputs
Table 3–1 describes the values that need to be specified in the Main
section of the PowerPlay Early Power Estimator.
Table 3–1. Main Section Information (Part 1 of 3)
Input Parameter Description
Family Select the device family.
The families supported are Stratix II, Stratix II GX, and HardCopy II.
Device Select your device.
Larger devices consume more static power and have higher clock dynamic power. All
other power components are unaffected by device.
Package Select the package that is used.
Larger packages provide a larger cooling surface and more contact points to the
circuit board, leading to lower thermal resistance. Package selection does not affect
dynamic power.
Temperature Grade Commercial devices have a maximum operating temperature of 85 °C. Industrial
devices offer 100 °C operation. Military devices offer 125 °C operation.
This field only affects maximum junction temperature. Currently, only Stratix II
supports the military temperature range.
Power Characteristics Select typical or theoretical worst-case silicon process.
There is process variation from die-to-die. This primarily impacts the static power
consumption. Maximum is used for thermal design, while Typical provides results
that line up with average device measurements. Currently, only Typical power
characteristics are available for the HardCopy II family.
Junction Temp, T
J
( o C) Enter the junction temperature of the device. This value can range from –55 °C to
125 °C. This field is only available when User Entered T
J
is selected.
In this case, junction temperature is not calculated based on the thermal information
provided.
Ambient Temp, T
A
(°C) Enter the air temperature near the device. This value can range from –55 °C to
125 °C. This field is only available when Auto Computed T
J
is selected.
If Estimated
θ
JA
is selected, this field is used to compute junction temperature
based on power dissipation and thermal resistances through the top-side
cooling solution (heat sink or none) and board (if applicable).
If Custom
θ
JA
is selected, this field is used to compute junction temperature
based on power dissipation and the custom
θ
JA
entered.