Usb2.0 impedance calculation
Mohan Hypo , 01-25-2022, 11:26 PM
How to calculate impedance for usb2.0 in pcb and can we connect usb shield with gnd through ferrite.
robertferanec , 01-28-2022, 07:52 AM
USB 2.0 impedance is usually 90 ohms (45 single ended). Here is a document which you can find useful:
Mohan Hypo , 01-28-2022, 11:42 PM
So, finally which one I prefer for the calculation...Saturn r else my pcb manufacturers
robertferanec , 02-07-2022, 08:43 AM
You have more options:
- The simplest is to use your PCB manufacturer's online calculator (often they have some - you select the stackup you would like to use and you can calculate the impedance and track geometry there) e.g. something like this https://cart.jlcpcb.com/impedanceCalculation
- or ask your PCB manufacturer to send you their standard stackup, impedances and all dimensions (you need to have direct contact in your PCB factory)
- or you can try to design your own stackup, approximately calculate the numbers in Saturn and then ask PCB manufacturer to confirm or adjust these numbers (not easy to do, can be expensive and can take a lot of time)
In your PCB, use the numbers from PCB manufacturer.
- The simplest is to use your PCB manufacturer's online calculator (often they have some - you select the stackup you would like to use and you can calculate the impedance and track geometry there) e.g. something like this https://cart.jlcpcb.com/impedanceCalculation
- or ask your PCB manufacturer to send you their standard stackup, impedances and all dimensions (you need to have direct contact in your PCB factory)
- or you can try to design your own stackup, approximately calculate the numbers in Saturn and then ask PCB manufacturer to confirm or adjust these numbers (not easy to do, can be expensive and can take a lot of time)
In your PCB, use the numbers from PCB manufacturer.
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