Issue link: https://iconnect007.uberflip.com/i/1163814
68 DESIGN007 MAGAZINE I SEPTEMBER 2019 and conductance, usually ranging from 25–125 ohms. Factors dictating impedance include: • The distance from other copper features • The width and thickness of the copper signal trace • The thickness of material on either side of the copper trace • The dielectric constant of board material You can save time, money, and effort if you are aware of the impedance math when you sit down to design your board. Gain this aware- A Proactive Approach to Controlled Impedance Most can agree that controlling impedance is critical to signal integrity and board perfor- mance in devices powering high-speed digital applications, telecommunications, or RF com- munications. How to do so is another matter. It is common practice to include impedance-re- lated notes with a PCB design and rely on the manufacturer to determine the proper trace pa- rameters. This inherently passive methodology often leads to delays, cost overruns, and even batches of useless boards. PCB trace impedance is determined by its in- ductive and capacitive reactance, resistance, Connect the Dots by Bob Tise, SUNSTONE CIRCUITS