All of the SDRAM output drivers I have measured have impedances of around 20
ohms. Adding the 22 ohm resistor is the usual way to use these parts. If you
are driving into a matched system having a characteristic impedance of 50
ohms (and end terminated) you will reduce the driver current by 2 dB.
In message
ofd2c30845.714f84dd-on652572d0.0047471b-652572d0.00489...@scmmicro.co.in
, dated Thu, 3 May 2007, kbalasubraman...@scmmicro.co.in writes:
In our ethernet device, by introducing series resistors of value 22
ohms in the Tx / Rx signals we noticed reduction in the emission
levels.
K,
The efficiency of your Ethernet cable as an antenna/as a transmission line
will depend on the matching of the impedance at each end of the cable. What
you have done with your 22R resistor is change the matching impedance at
that end of the cable as well as reducing the signal current in the
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