Re: SPICEing The Inductance of a Trace Over a Ground Plane?

On Mon, 17 Sep 2007 20:38:29 -0700, John Larkin
<jjlarkin@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx> wrote:

On Tue, 18 Sep 2007 02:27:00 GMT, D from BC <myrealaddress@xxxxxxxxx>
wrote:

[snip]

Aside from the 50% signal loss, invalid CMOS levels and a hot pulse
generator...the great is the 10cm strip acts like it's not even
there....if I got that right..


D from BC



You can also "source terminate" a transmission line....



<-------tx line-------------->

+5v +5v
| |
| |
gate----R1------------------------------gate
driver receiver
| |
| |
gnd gnd



If R1 is close to the driver and equal to the line impedance, you get
a perfect 5 volt step at the receiver, no problems, no ringing, no
static power dissipation.

John


I think I read somewhere that open ended transmission lines can
reflect..
I haven't given it much thought yet and don't know if it's a digital
concern.

I'm wondering if PC motherboards use some sort of termination for long
PCB traces passing high speed digital..?


D from BC
.