ISS Technology Update, Volume 7 Number 5 - Newsletter

ISS Technology Update Volume 7, Number 5
6
Meet the Expert—Michael Chan
Michael Chan’s 18-year career with Compaq/HP is proof that “timing is everything.” Michael has excelled in signal integrity
(SI) engineering due to his discipline and attention to detail. SI, which addresses signal timing and quality, is a critical
technology that impacts all levels of server platform design. SI analysis is performed using computer simulation because
signaling problems are extremely difficult to diagnose and solve after a system is built. If signaling problems are not understood
and solved prior to PCB fabrication, they can cause delays that increase the project cycle and development cost.
Michael began his career creating Spice models and working on Simultaneous
Switching Noise Analysis for ASIC package designs. Then he worked on
electromagnetic interference (EMI) design for various desktops, portables, servers,
array controller cards, and printers. After that he worked on device and system
level SI in the portable division. Since then, he has made significant contributions
to ISS platform designs, including the first Itanium servers, AMD servers, and now
BladeSystem servers. According to Michael’s manager, Mike Pelonero, “The SI
aspect of these designs has become more critical as processor, memory, and
overall system frequencies have increased as have design densities, especially
with regard to blade servers”
Michael’s expertise seems to spill over into some of his hobbies, and vice versa.
He enjoys audio amplifier construction, cassette deck repairs, plastic model
construction, and stamp collecting. He is the father of three—twins (a girl and boy)
age 11 and a boy age 8.
Below are excerpts from an interview with Michael Chan.
Why did you decide to become an engineer?
Ever since I was a kid, I’ve liked to build and repair stuff. In order to build things,
one needs to know how to meet the design specifications. At the same time,
repairing something requires one to understand how it works and why it broke. It
seems like engineering was my destiny.
What has been one of your most interesting research projects?
One of my most interesting research projects was analyzing the effect of high-
frequency decoupling capacitors on laptop computers. We used to put a lot of
high-frequency decoupling capacitors with many different capacitance values into
our laptop products. The decision to use that many capacitors was based on rules
of thumb. This practice increased both the cost of the product as well as component inventory costs.
Name: Michael Chan
Title: Hardware Design Engineer (ISSG)
Years at HP: 18
Patents:
• Chan, Michael Y., Leigh, Kevin B.
“Apparatus For Controlling The
Impedance of High-Speed Signals
on A Printed Circuit Board.” U. S
Patent 5764489. June 9, 1998.
• Chan, Michael Y., Leigh, Kevin B.
“Apparatus For Controlling The
Impedance of High-Speed Signals
on A Printed Circuit Board.” U. S
Patent 5986893. November 11,
1999.
• Chan, Michael Y., Riley, Dwight D.
“Point-To-Point Electrical Loading For
a Multi-Drop Bus.” U. S. Patent
7099966. August 29, 2006.
University/Degree
• University of Arizona at Tucson:
Bachelor of Science Geosciences
• University of Arizona at Tucson:
Master of Science Electrical
Engineering”
We made some emission measurements on one laptop and found out that there was very little difference in terms of emission
level detected between a laptop that is fully populated with high-frequency decoupling capacitors and one with no capacitors.
At that moment, we still did not know if the capacitors were ineffective or whether something caused those capacitors to
become ineffective.
We then performed some computer simulations and found out that the capacitor mounting structure had so much inductance
that it rendered all the capacitors ineffective. We modified the design of the mounting structure and repeated the simulation.
We also reduced number of capacitors, and the emission level improved significantly. We finally decided to reduce the number
of high-frequency capacitors as well as the capacitance values of those being used. This significantly reduced the component
cost in our future laptop products.