Setting Operating Conditions

Operating Conditions, Step 3 of the Device Selection Wizard, enables you to define the voltage and temperature ranges a device encounters in a working system. The operating condition range entered here is used by Timer, the timing report, and the back-annotation function. These tools enable you to analyze worst-, typical-, and best-case timing.

Junction Temperature

Select a junction temperature. Supported ranges include:

Consult the Actel Data Sheet, available at http://www.actel.com/techdocs/ds/index.html, to find out which temperature range you should use.

If you select Custom, edit the Best, Typical, and Worst fields. Modify the range to the desired value (real) such that Best < Typical < Worst.

You can calculate junction temperature from values in the Actel Data Sheet, available at http://www.actel.com/techdocs/ds/index.html.

The temperature range represents the junction temperature of the device. For commercial and industrial devices, the junction temperature is a function of ambient temperature, air flow, and power consumption.

For military devices, the junction temperature is a function of the case temperature, air flow, and power consumption. Because Actel devices are CMOS, power consumption must be calculated for each design. For most low power applications (e.g. 250mW), the default conditions should be adequate.

Performance decreases approximately 2.5% for every 10 degrees C that the temperature values increase. Refer to the SmartPower online help for more information about power consumption.

Voltage

Select a voltage:

If you select Custom, you may choose from Best > Typical > Worst in the drop-down menu.  

Radiation Derating

Conservative post-radiation performance estimates are available for some radiation tolerant devices based upon the number of KRads the device is expected to be subjected to. Radiation effects vary by device lot and may not be completely representative of the lot you are using. Post-radiation timing numbers are only meant to be a guide and are not a guarantee of performance. Customers must consult the specific radiation performance report for the specific lot used. Post radiation exposure estimates currently only affect timing numbers. The SmartPower power analysis tool is not affected by changing the radiation exposure value.

RTSX-S and RTAX-S  ONLY - Radiation Derating

This option is only available for RTSX-S and RTAX-S devices. The valid range is integer values from 0 to 300, and the units are in KRads. Modifying this selection impacts the timing derating in Timer and back-annotating SDF files, so when you modify this value, you must extract a new SDF file from Designer and re-evaluate the timing of your design. It does not affect the device configuration.