How do you all get around the same length?

黑屋白巫

How do you all get around the same length? [Copy link]

Is it concentrated at the outlet end, or is it “dynamically equal length”?

Has anyone studied the effect of local loose coupling on signals? Does the increase in local line spacing lead to unstable impedance?

I tried Allegro's dynamic equal length today, and it was like suppressing one problem but causing another to pop up. I don't quite understand the logic of Allegro.

黑屋白巫

Should I try to limit the number of equal length exercises, or does it not matter much and I can just add more tunes?

Target rate 20G

btty038

Only pay attention to equal length and make appropriate compensation, but the speed is not simulated and almost has not turned over, meets the project requirements,

常见泽1

When I just graduated, I bought a USB card and asked for equal length. I also used the built-in function of Allegro to pull it directly.

秦天qintian0303

btty038 posted on 2024-3-5 23:08 Only focus on equal length and make appropriate compensation, but the speed is not simulated and has almost not turned over,, meet the project requirements,,

The same is true for USB, which is designed for high-speed applications.

btty038

Qintianqintian0303 posted on 2024-3-6 12:09 The same is true for USB. Basically, there are too few designs for high-speed applications.

Just USB, network port, 422, 232, SPI, and above that are almost all DDR in the board, etc.

btty038

However, the boards are professionally wired, and we do some peripheral conversions, so the requirements are not particularly high.

damiaa

It is said that dynamic equal length is better, and where there is a difference, it should be supplemented.

qwqwqw2088

The target rate is 20G, so you need to draw the same length

It's not a super high speed, so don't set too high a standard.

ken1023

Local loose coupling has little effect on the signal, and the increase in local line spacing will basically not cause a large change in impedance, especially for the routing inside the BGA chip. The routing after the BGA should still try to ensure the line width and coupling.