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Do you put series termination resistor on the driver or receiver side?

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series termination resistor to reduce signal intergrity issue.
1)you want to put on the driver side or receiver side?
2)Does series resistor reduce the amplitude of signal?
3)series termination is easier than parallel termination therefore it's more popular?
 

Driver side, Zo/2 (net, including driver active device Ron).
Amplitude is reduced by 2 at DC (simple resistive division)
Not easier per se but draws less current than a near-end
shunt termination, shunt term needs an output that looks
like a current source (infinite Z, so Zline = Zterm not
Zterm || Zdriver). A CMOS bang-bang output is low Z and
would probably not match well or consistently with a
parallel near end termination.
 

dick_freebird said:
Driver side, Zo/2 (net, including driver active device Ron).
Amplitude is reduced by 2 at DC (simple resistive division)
Not easier per se but draws less current than a near-end
shunt termination, shunt term needs an output that looks
like a current source (infinite Z, so Zline = Zterm not
Zterm || Zdriver). A CMOS bang-bang output is low Z and
would probably not match well or consistently with a
parallel near end termination.
Click to expand...

1) driver side so that there won't reflection back side from receiver side?
2)If line impedance is 50 Ohm, so the series resistor would be 25 ohm, and the driver output impedance Ron=25ohm?
what if driver output impedance is 100 Ohm, what would be the series resistor value?
 

The total series resistance should equal the characteristic transmission line impedance of the line being driven.

If the output impedance is higher than the line impedance, then you would need to add a resistor to ground so that the equivalent impedance matches the line impedance.
This, of course, will reduce the signal amplitude.
 

depends on rise time and prop delay.

, but you want Zd=Zo=Zr which reduces open cct V to 50% but without ringing or glitches with suitable layout. Controlled impedance gives widest bandwidth without ringing. Some CMOS is 50 and some 25 Ohm's, older style higher like 300 Ohms

Be specific.
 

Simple answer is, your cable has a characteristic impedance.
Ideally both ends of the cable should be correctly terminated at that impedance.

At the low impedance driving end, that may require some extra series resistance to raise the impedance.
At the high impedance receiving end, it may require a shunt resistor to lower the impedance.
 

The original question can't be answered without referring to applications and signal types.

In RF and GBit digital transmission, both side termination is useable. It involves reducing the signal magnitude to 0.5.

In case of digital signal transmission below GBit speed, different logic standards require different termination schemes (if termination is used at all).

LVDS and high voltage differential standards (e.g. RS422/RS485) are using load side parallel termination. High speed CMOS point-to-point connections mostly uses source side series termination. Part or all of the series resistor can be already implemented by the driver output impedance. Programmable logic chips and processor can have a selectable driver impedance.
 

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