Altera PowerPlay Early Power Estimator - Manual (Page 14)

3–2 Chapter 3: Using Cyclone III PowerPlay Early Power Estimator
PowerPlay Early Power Estimator Inputs
PowerPlay Early Power Estimator User Guide for Cyclone III FPGAs © June 2009 Altera Corporation
Table 3–1 describes the values that must be specified in the Main section of the
PowerPlay Early Power Estimator.
Table 3–1. Main Section Information (Part 1 of 2)
Input Parameter Description
Family Select the device family.
Only the Cyclone III device family is available.
Device Select your device.
Larger devices consume more static power and have higher clock dynamic power. All other
power components are unaffected by the 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 Select the appropriate temperature grade.
This field only affects the maximum junction temperature.
Power Characteristics Select the typical or theoretical worst-case silicon process.
Currently, only the typical silicon process is available for Cyclone III LS devices.
There is process variation from die-to-die. This primarily impacts the static power
consumption. Typical provides results that line up with average device measurements.
Junction Temp, T
J
(°C) Enter the junction temperature of the device. This value can range from 0°C to 85°C for
commercial grade devices and -40°C to 100°C industrial grade devices.
This field is only available when you select User Entered T
J
. 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 field is only available when you select Auto
Computed T
J
.
If Estimated Theta 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 Theta JA is selected, this field is used to compute junction temperature based on
power dissipation and the custom

JA
entered.
Heat Sink Select the heat sink being used. You can specify no heat sink, a custom solution, or specify a
heat sink with set parameters. This field is only available when you select Auto Computed T
J
and Estimated Theta JA.
Representative examples of heat sinks are provided. Larger heat sinks provide lower thermal
resistance and thus lower junction temperature. If the heat sink is known, refer to the data
sheet and enter a Custom heatsink-to-ambient value according to the airflow in your system.
The heat sink selection updates 
SA
and the new value is seen in the Custom 
SA
(°C/W)
parameter. If you select a custom solution, the value is the same as the value entered for
Custom

SA
(°C/W).
Airflow Select an available ambient airflow in linear-feet per minute (lfm) or meters per second (m/s).
The options are 100 lfm (0.5 m/s), 200 lfm (1.0 m/s), 400 lfm (2.0 m/s), or still air. This field
is only available when you select Auto Computed T
J
and Estimated Theta JA.
Increased airflow results in a lower case-to-air thermal resistance and thus lower junction
temperature.