Description
The power consumption of a device that is powered, but not configured, can be estimated by using the PowerPlay Early Power Estimator (EPE) or the Quartus® II PowerPlay Power analysis tool. Using either of these tools, you should create a design with minimal or no resources used so you can estimate the device static current consumption. This will be representative of the device power consumption prior to device configuration with the following exceptions:
- The I/O static power will be larger than the tool estimate prior to configuration due to the weak pull up resistors being active. All of Altera®'s devices that support hotsocketing will tri-state the I/O pins and pull them to VCCIO through a weak pull up resistor. You can look in the device datasheet to determine the weak pull up resistor value and manually calculate the potential DC current that will flow through each I/O pin, and multiply that value by the number of I/O pins in the device. Stratix® - series devices have a dedicated pin (nIO_PULLUP) which can be used to disable the weak pull up resistor prior to device configuration.
- The analog PLL current could be higher prior to configuration than reported by the Quartus II PowerPlay Power analysis tool. When PLLs are not used in a design, the VCO will be shut down to minimize power. Prior to configuration, the VCO will be running, thus you can use the EPE to estimate the power consumed by the analog PLL voltage supply by entering a value for the VCO frequency. For a conservative power estimate, you should enter a VCO frequency toward the high end of the supported VCO range as specified in the device datasheet.