Early Power Estimator User Guide

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ID 683272
Date 7/16/2021
Public
Document Table of Contents
Document Table of Contents x
1. Early Power Estimator Overview 2. Setting Up the Early Power Estimator 3. Early Power Estimator Worksheets 4. Factors Affecting the Early Power Estimator Spreadsheet Accuracy A. Additional Information for Early Power Estimator User Guide
1. Early Power Estimator Overview x
1.1. Release Information 1.2. Power Model Status for Supported Device Families
2. Setting Up the Early Power Estimator x
2.1. System Requirements 2.2. Download and Install the Early Power Estimator 2.3. Estimating Power Consumption
2.2. Download and Install the Early Power Estimator x
2.2.1. Changing the Macro Security Level in Microsoft Excel 2003 2.2.2. Changing the Macro Security Level in Microsoft Excel 2007 2.2.3. Changing the Macro Security Level in Microsoft Excel 2010
2.3. Estimating Power Consumption x
2.3.1. Estimating Power Consumption Before Starting the FPGA Design 2.3.2. Estimating Power Consumption While Creating the FPGA Design 2.3.3. Estimating Power Consumption After Completing the FPGA Design
2.3.1. Estimating Power Consumption Before Starting the FPGA Design x
2.3.1.1. Entering Information into the Early Power Estimator
2.3.1.1. Entering Information into the Early Power Estimator x
2.3.1.1.1. Manually Entering Values
2.3.2. Estimating Power Consumption While Creating the FPGA Design x
2.3.2.1. Importing a File
2.3.2.1. Importing a File x
2.3.2.1.1. Generate the EPE File 2.3.2.1.2. Import Data into the EPE Spreadsheet
3. Early Power Estimator Worksheets x
3.1. Main Worksheet 3.2. Logic Worksheet 3.3. RAM Worksheet 3.4. DSP Worksheet 3.5. I/O Worksheet 3.6. PLL Worksheet 3.7. Clock Worksheet 3.8. HSDI Worksheet 3.9. XCVR Worksheet 3.10. HMC Worksheet 3.11. IP Worksheet 3.12. HPS Worksheet 3.13. Report Worksheet 3.14. Enpirion Worksheet
3.1. Main Worksheet x
3.1.1. Input Parameter 3.1.2. Thermal Power 3.1.3. Power Tree Design 3.1.4. Thermal Analysis
3.1.4. Thermal Analysis x
3.1.4.1. Not Using a Heat Sink 3.1.4.2. Using a Heat Sink
3.13. Report Worksheet x
3.13.1. Static Power and Dynamic Current per Voltage Rail 3.13.2. Power Up Current 3.13.3. Power Breakout for Multiple Voltage Supplies 3.13.4. Power Regulator Settings
4. Factors Affecting the Early Power Estimator Spreadsheet Accuracy x
4.1. Toggle Rate 4.2. Airflow 4.3. Temperature 4.4. Heat Sink
A. Additional Information for Early Power Estimator User Guide x
A.1. Document Revision History for Early Power Estimator User Guide
1. Early Power Estimator Overview
2. Setting Up the Early Power Estimator
3. Early Power Estimator Worksheets
4. Factors Affecting the Early Power Estimator Spreadsheet Accuracy
A. Additional Information for Early Power Estimator User Guide

4.2. Airflow

It is often difficult to place the device adjacent to the fan providing the airflow. The path of the airflow might traverse a length on the board before reaching the device, thus diminishing the actual airflow the device receives. The following figure shows a fan that is placed at the end of the board. The airflow at the FPGA is weaker than the airflow at the fan.

Figure 30. Airflow and FPGA Position

You must also consider blocked airflow. The following figure shows a device blocking the airflow from the FPGA, significantly reducing the airflow seen at the FPGA. The airflow from the fan also has to cool board components and other devices before reaching the FPGA.

Figure 31. Airflow with Component and FPGA Positions

If you are using a custom heat sink, you do not need to enter the airflow directly into the EPE spreadsheet but it is required to enter the θSA value for the heat sink with the knowledge of what the airflow is at the device. Most heat sinks have fins located above the heat sink to facilitate airflow. The following figure shows the FPGA with a heat sink.

Figure 32. Airflow and Heat Sinks

When placing the heat sink on the FPGA, the direction of the fins must correspond with the direction of the airflow. A top view shows the correct orientation of the fins.

Figure 33. Heat Sink (Top View)

These considerations can influence the airflow at the device. When entering information into the EPE spreadsheet, you have to consider these implications to get an accurate airflow value at the FPGA.

Level Two Title