AN 750: Using the Altera PDN Tool to Optimize Your Power Delivery Network Design

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ID 683155
Date 7/08/2015
Public
Document Table of Contents
Document Table of Contents x
1. AN 750: Using the Altera PDN Tool to Optimize Your Power Delivery Network Design
1. AN 750: Using the Altera PDN Tool to Optimize Your Power Delivery Network Design x
1.1. Impact of a Poor PDN 1.2. PDN Circuit Topology 1.3. Estimating the Current Requirements of your FPGA Design 1.4. Calculating Ztarget 1.5. Example Design 1.6. PDN Design Optimization Study 1.7. Document Revision History
1.3. Estimating the Current Requirements of your FPGA Design x
1.3.1. FPGA Functional Blocks 1.3.2. Clock Frequencies 1.3.3. GPIO 1.3.4. Transceivers 1.3.5. Data Patterns
1.6. PDN Design Optimization Study x
1.6.1. Initial Stackup Entry 1.6.2. Using the Correct Number of Power/Ground Via Pairs 1.6.3. Using the Correct Number of Power/Ground Via Pairs and Layer Number 1.6.4. Corrected Number of Power/Ground Via Pairs and Layer Numbers 1.6.5. Moving Supplies to Optimal Layers 1.6.6. Moving Power and Ground Planes Closer Together 1.6.7. Move Decoupling Capacitors to the Top Surface of the PCB 1.6.8. Using X2Y Decoupling Capacitors 1.6.9. Using Ultra–Low ESR Bulk Capacitors 1.6.10. Swapping VCC on Layer 9 with VCC, VCCT_GXB, and VCCR_GXB on Layer 4 1.6.11. Assessing How Much Total Capacitance Might be Required 1.6.12. Using the Core Clock Frequency and Current Ramp Up Period Parameters 1.6.13. Overall Design Study Capacitor Savings 1.6.14. Overall Summary 1.6.15. References
1. AN 750: Using the Altera PDN Tool to Optimize Your Power Delivery Network Design

1.3.5. Data Patterns

Power requirements depend on toggle % of the logic in your design. A clock-like data pattern has higher current requirements than a PRBS pattern. A PRBS pattern has higher current requirements than those for a grey-code pattern.

Use the highest toggle % that you expect to see in your design. The PDN design becomes difficult if you over estimate. Although it is design dependent, Altera assumes a 12.5% toggle percentage. Use the PPPA to analyze the toggle % of your design.

When using the Quartus PPPA, base your power estimations on simulation-based input data. It provides accurate power estimations.

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