Where we use impedance control board?

[KP]

why use routing with impedance control

Hi

In what condition or related field i mean what kinda design to use impedance control board?Is that impedance control board got somethin' to do with total / maximum power transfer?Usually I heard of the 50 Ohm impedance control and so on... what is the difference between 50 Ohm and 75 Ohm impedance control?

Kindly say 'Thank Q' to those who r helpful.

Best Regards
KP

 

[power-twq]

routing impedance control

when signal's transition time is less then 1/2 pcb trace delay time,

the reflection of signal will become serious.

you must use impedance control board, it is generally not use for

transferring maximum power, it is for minimizing reflection and

keep signal's integrity.

50R is generally used in communication field, 75R is generally

use in TV field (perhaps this is not always true).

but 50R board can tolerant more capacitance load than 75R board

for its low impedance.

Do you know, now every mother board is impedance controlled board.

best regards

Hi

In what condition or related field i mean what kinda design to use impedance control board?Is that impedance control board got somethin' to do with total / maximum power transfer?Usually I heard of the 50 Ohm impedance control and so on... what is the difference between 50 Ohm and 75 Ohm impedance control?

Kindly say 'Thank Q' to those who r helpful.

Best Regards
KP

 

[jdhar]

Impedance Control Board

If the signals rise time is less than 1/6th the electrical length, you need controlled impedance - ie, if you have a 1 ns rise time, 1 ns / ~.18 ns/inch (in FR4) = 5.5 inches / 6 ~ 1 inch. With a trace length of 1 inch or less, you could get away without controlled impedance. Otherwise, you would need it.

 

[vij]

Re: Impedance Control Board

controlled impedance is reqired fro routing fast rise time signals
if rise time time is fast then rise time length of signal routed reduced
if routed lenght is more than rise time length then route acts as transmission line

for transmission line controlled impedance is required

with regard

vij

 

[pvskt]

Re: Impedance Control Board

Impedance control is mainly for Max power transfer from dirver to the recevier.

 

[jdhar]

Re: Impedance Control Board

Impedance control is mainly for Max power transfer from dirver to the recevier.

I don't agree with that - I think that may be true a lot of the time, but in digital, it is definitely used to terminate transmission lines so reflections and signal bouncing do not occur.

 

[pvskt]

Re: Impedance Control Board

Shall I ask you when reflection and bouncing occurs??

It occurs due to impedance mismatch. If there is impedance mismatch how will max power be delivered at the load? If max power is not delivered at the load, how will the threshold levels be properly recognized? The resultant is reflection and other sign effects.