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Mark Otto, Sr Hardware Engineer,
Teradyne
Mark Otto received his bachelor's
degree in electrical and computer
engineering from the University of
Minnesota Duluth and his master's degree
from Concordia University. He has more
than twenty years of experience in the
power engineering industry, working on
both AC/DC and DC/DC power conversion.
He currently works for Teradyne in the
Semiconductor Test division, where he is
responsible for the power architecture of
Teradyne's digital instruments.
Providing power to field-programmable gate arrays (FPGAs) that are running a
multi-gigabit serializer/deserializer while drawing 100 amps of core voltage, such as
state-of-the-art FPGAs from Xilinx and Intel/Altera, is becoming a serious challenge
for power architects and engineers. High dynamic currents demanded by processors
and FPGAs can cause significant voltage deviations on the core rails. Careful design
of the power distribution network (PDN) can mitigate these problems.
The PDN has three basic components: resistance, inductance, and capacitance.
The goal is to use these components in the most effective way to help reduce the
overall impedance of the PDN. How you do that is largely dictated by physics. The
impedance curve is a summation of the effects of the power source you choose,
the bulk capacitors, high-frequency capacitors, the printed circuit board (PCB),
the integrated circuit (IC) package, and the die inside the IC package. Component
relationships can be tricky. Simulation software helps reduce board spins by
simulating all aspects of the boards, power density, voltage drops, plane impedance,
signal integrity, and other things. Simulation is expensive, however, so its use often
depends on the type of product you are designing.
Simulation Is Key to Resolving Design Trade-Offs
"The PDN has three basic components: resistance, inductance,
and capacitance. The goal is to use these components in the most
effective way to help reduce the overall impedance of the PDN."
