Calculating the power dissipation of field programmable gate arrays (FPGAs) is similar to using the calculations for other CMOS ASIC devices, such as gate arrays and standard cells. The power dissipation depends on such factors as utilization, average operating frequency, and load conditions. In contrast, most PALs and PLDs have a fixed power consumption.
This application note discusses power dissipation and the concept of equivalent power capacitance. The general approach to calculating power in an Actel device will be described using equivalent power capacitance values for the
devices. This general equation is useful if internal switching frequencies can be accurately determined. Since this is often difficult to do, a set of approximation curves based on average frequency rules of thumb are provided. The graphs provide an upper limit estimate for active power sufficient for most
designs.
Access the entire application note on the Actel Corp. website.
