Issue link: https://resources.pcb.cadence.com/i/1534337
Contents Part 1: Understanding High-Speed Digital Design Problems ............................................................................................................... 3 The High-Speed Design Challenge ............................................ 3 Enter OrCAD X and Presto PCB Editor....................................... 4 Introduction to High-Speed PCB Design ................................. 4 What Defines High-Speed Design? .................................... 4 Key Areas of Concern in High-Speed Design ................. 5 Constraint Management in OrCAD X ............................ 5 High-Speed Design Problems in Practice ....................... 6 1. Impedance Discontinuities .......................................... 6 Common Causes of Impedance Discontinuities ....... 6 Solution Implementation in OrCAD X ........................... 7 Practical Tips for Managing Impedance in High-Speed Designs .................................................................................. 7 2. Signal Reflections, Ringing, and Crosstalk ............. 7 Signal Reflections and Ringing ......................................8 Crosstalk Between Traces ...............................................8 Practical Tips for Mitigating Reflections and Crosstalk ................................................................................................. 9 3. Ground Bounce and Power Distribution Noise (PDN) ................................................................................................. 9 4. Electromagnetic Interference (EMI) and Electromagnetic Compatibility (EMC) ......................... 11 Managing These Issues with OrCAD X ....................... 12 PCB Transmission Lines and Controlled Impedance .......... 12 Types of Transmission Lines ............................................. 12 Key Factors Affecting Impedance Control .................... 13 Basics of Routing Differential Pairs and Length Matching .................................................................................................... 14 PCB Stackup Design ..................................................................... 14 High-Level Overview of Stackup for High-Speed Designs .................................................................................................... 14 Material Selection Considerations ................................... 15 Practical Tips for Stackup Design.................................... 16 Electromagnetic Interference (EMI) and Electromagnetic Compatibility (EMC) ....................................................................... 16 Electromagnetic Interference (EMI) ................................ 16 Electromagnetic Compatibility (EMC) ............................. 16 Practical Tips for Managing EMI and EMC in High-Speed Designs .....................................................................................17 Power Integrity ................................................................................17 Overview of Power Distribution Network (PDN) Design .....................................................................................................17 Key Causes of PDN Noise ....................................................17 Simplified Design and Analysis Methods ....................... 18 Practical Tips for PDN Design ........................................... 18 High-Speed PCB Layout Design ............................................... 19 Key Component Placement Strategies .......................... 19 High-Level Routing Techniques ...................................... 20 Signal Return Paths and Via Design .............................. 20 Practical Tips for High-Speed Layout ............................ 21 Post-Route Verification and Analysis ......................................22 Design Rule Checks and Post-Layout Analysis ...........22 Design Rule Checks (DRC) .................................................22 Signal Integrity Analysis .....................................................22 2 www.cadence.com OrCAD X High-Speed Digital Design Guide