58 DESIGN007 MAGAZINE I JULY 2018
References:
1. Barry Olney's Beyond Design columns:
Controlling the Beast, A New Slant on
Matched Length Routing, Board-Level Simula-
tion and the Design Process: Plan B – Post Lay-
out Simulation.
2. High-Speed Signal Propagation, by How-
ard Johnson.
3. All simulations performed in HyperLynx
LineSim.
Barry Olney is managing director of
In-Circuit Design Pty Ltd (iCD), Aus-
tralia, a PCB design service bureau
that specializes in board-level
simulation. The company developed
the iCD Design Integrity software
incorporating the iCD Stackup, PDN and CPW Planner. The
software can be downloaded from www.icd.com.au. To
contact Olney, or read past columns, click here.
Molecular electronics, which aims to use molecules to
build electronic devices, could be the answer. But until
now, scientists haven't been able to make a stable device
platform for these molecules to sit inside which could reli-
ably connect with the molecules, exploit their ability to
respond to a current, and be easily mass-produced.
An international team of researchers, including Mac-
quarie University's Associate Professor Koushik Venkate-
san, have developed a proof of concept device which
they say addresses all these issues. The team exploited
the fact that metallic nanoparticles can provide reliable
electrical contacts to individual molecules, allowing them
to transport charge through a circuit.
"Imagine a miniaturised transistor made up of several
single molecules," says Koushik. "That's the promise of
molecular electronics—devices that are smaller, faster,
have more memory and are cheaper to make."
Koushik is confident their research will open up the
bottleneck for this molecular-based technology to move
forward.
"This fundamental research is extremely exciting
as it points the way to practically 'wiring molecules' by
exploiting the fact that Koushik and his colleagues have
made a metallic nanoparticle provide a reliable electrical
contact to individual molecules," says Professor Alison
Rodger, Head of the Department of Molecular Sciences at
Macquarie University.
"It is amazing to think that this work leads the way
to true molecular-sized electronic circuits."
Click here for more.
The Future of Electronics is Chemical
• If the supply voltage drops from 3.3V to
1.5V, then the allowable noise margin
more than halves.
• Differential technologies do not have the
noise margin concerns of single-ended
technologies. This is due to common-
mode rejection.
• The total crosstalk on a victim trace is the
accumulated noise injected from all
nearby noise sources.
• Forward crosstalk does not exist in the
stripline configuration. The amplitude of
the crosstalk is also considerably reduced.
• The simulator should be set to 150mV
maximum crosstalk on all signals. However,
crosstalk from within the same group, on
synchronous buses, can be ignored unless
the frequency is extremely high.
• Both forward and reverse crosstalk can be
reduced by separating the aggressors
from the victim traces or by reducing
the height of the dielectric above/below
the planes.
