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Equipment designs increasingly
utilize advanced MCU, DSP and
FPGA devices to deliver the
functionality and performance
demanded of them. With
this sophistication comes the
challenge of providing the
multiple power rails these
devices require. The use
of carefully chosen power
modules can significantly ease
this task and allow system
designers to get to market on
time and without compromise.
A quick examination of almost
any piece of industrial and
telecommunications equipment will
clearly show that it requires a large
number of individual DC bus voltages
operating at different currents to
provide power to all the sub-circuits
in the design. Each DC bus voltage is
typicallysuppliedbyaDC-DCswitching
regulator or an LDO that has to fit in
ever smaller PCB footprints and yet
meet tighter and more demanding
performance specifications relating
to efficiency, input and output
voltage regulation, and operating
temperature, to mention a few.
These specifications are necessary
to ensure the equipment can operate
for longer, run cooler and achieve
higher reliability. In order to design
these converters in-house, electronic
equipment companies must employ
highly qualified and experienced
power engineers and, depending
on the number of converters
needed, allow sufficient time in the
project schedule for the design and
prototyping of the power system,
including full test and verification.
This is a process that is expensive and
time consuming, impacting both the
project budget and time-to-market
in a very competitive market where
time and cost are rare commodities.
A “Wish List” for the ultimate power
system design
From a cursory analysis of subsystem
power requirements it is a short step
to identifying a wish list for an ideal
power delivery solution, which must:
1. Meet the most stringent
specifications of the subsystem, e.g.
voltage tolerance.
2. Operate with the highest possible
efficiency - this allows battery-
powered devices to last longer and
reduces power dissipation so that
devices can run cooler and be more
reliable. Every 10C rise in operating
temperature halves the Mean Time
Between Failure (MTBF).
3. Provide excellent transient
response for FPGA and CPU operation
to avoid spurious operation caused
by false clocking or incorrect power
sequencing.
4. Offer a programmable output
Power Modules - In Search of a Winning
Combination
Jon Cronk, Exar Corporation
20 l New-Tech Magazine Europe