why series termination is Not able to drive multiple loads

Thread Starter

hoyyoth

Joined Mar 21, 2020
132
Dear Team,

May I know why series termination is not able to drive multiple loads?

Is it due to increased rise time and less current drive strength?

Regards
Hai
 

DickCappels

Joined Aug 21, 2008
7,836
It depends upon how many transmission lines are being driven. If it is only 1 transmission line with terminations at taps you would find reflections from each tap.
 

Deleted member 115935

Joined Dec 31, 1969
0
Series termination

https://practicalee.com/termination/

what the series resistance does is match the line impedance to the driver impedance,
so the signal is launched, and is only at half volts till it hits the end, where its now reflected to make full voltage.
The effect is to slow the edge,

Now if you drive say two loads, off one resistor, then one is going to not be at the end,
so its going to initially see half volts,

In reality, if two loads are "close" then its generally Ok, but what means close depends upon the edge speed you want.
another option, is to use two series resistors in parallel, each sending to its own line / load.

But generally, keep one load on each output
 

Thread Starter

hoyyoth

Joined Mar 21, 2020
132
Series termination

https://practicalee.com/termination/

what the series resistance does is match the line impedance to the driver impedance,
so the signal is launched, and is only at half volts till it hits the end, where its now reflected to make full voltage.
The effect is to slow the edge,

Now if you drive say two loads, off one resistor, then one is going to not be at the end,
so its going to initially see half volts,

In reality, if two loads are "close" then its generally Ok, but what means close depends upon the edge speed you want.
another option, is to use two series resistors in parallel, each sending to its own line / load.

But generally, keep one load on each output
Hi Andrew,

Thank you.

Regards
HARI
 
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