and SONET/SDH OC-3/12/48
applications. Packaged in a 24 lead
4 x 4 mm QFN package, the Si5338
and Si5334 devices are available at
prices starting at $9.31 in 10,000
piece quantities, depending on
output frequency.
MEMS MIKES FOR
CONSUMER APPS
Early in 2007, Scotland's Wolfson
Microelectronics (www.wolfson
micro.com) acquired a local MEMS
design company, Oligon Ltd., which
was integrated into Wolfson's plans
to add more hardware and software
technologies to its audio processing,
A/D, and D/A technology. In October,
this emerged as a new family of
silicon microphones, beginning with
the WM7110 and WM7120.
These are compact, high signal-to-noise ratio (SNR) analog mikes for
use in consumer applications that
require low power consumption and
high signal quality. Using Wolfson's
CMOS/MEMS membrane technology,
the new devices promise high
reliability and performance in a
miniature, low profile package.
Wolfson is also offering enhanced
WM7110E and WM7120E versions,
which are said to be the first MEMS
silicon microphones to deliver a
sensitivity tolerance of ±/-1 dB. The
WM7110 ( 4. 72 x 3. 76 x 1.25 mm)
and ultra-compact WM7120 ( 3. 76 x
2.95 x 1.10 mm) devices typically
consume only 160A. making them
ideal for portable applications such
as mobile phones, portable media
players, digital still cameras, video
cameras, navigation devices, and
noise-cancelling headphones.
Both offer 62 dB SNR
(A-weighted) performance and total
harmonic distortion of 0.5% max at
100 dB SPL. Sample quantities should
be available by the time you read
this. Prices start at $1.64 in quantities
of 1,000.
INDUSTRY AND
THE PROFESSION
INTEL RECOGNIZED
BY EPA
impact in advancing the renewable
energy market.
Early in the year, Intel signed a
multi-year commitment to purchase
more than 1.3 billion k W/hr of
renewable energy certificates
(REC) per year, which will meet
approximately 47 percent of its
purchased electricity use. The
commitment put the company at
the No. 1 spot on the EPA Fortune
500 Green Power Partners list.
The EPA estimates that Intel's
purchase has the equivalent
environmental impact of taking
more than 185,000 cars off the road
or avoiding the amount of electricity
needed to power more than 130,000
average American homes.
DON'T MIX
HEADPHONES AND
PACEMAKERS
At an award ceremony hosted by
the US Environmental Protection
Agency (EPA) late in October, Intel
Corporation ( www.intel.com)
received a 2008 Green Power
Leadership Award and was also
named a Green Power Partner of
the Year. The EPA recognized the
company's voluntary efforts to
address climate change through
green power purchases and its
According to a recent study
conducted by Harvard Medical
School's Beth Israel Deaconess
Medical Center ( www.bidmc.org),
if you possess both an MP3 player
and a pacemaker or implanted
defribrillator, you may be in trouble.
Research presented at the
American Heart Association's
Scientific Sessions 2008 indicated
that headphones for MP3 players
(which typically include magnetic
neodymium), if placed within an
inch of pacemakers and implantable
cardioverter defibrillators (ICDs),
may interfere with their operation.
When exposed to magnets,
these devices automatically pace,
sending low energy signals to the
heart to make it beat. Defibrillators
— which treat slow and dangerously
fast heart rhythms — send either
low or high energy signals to the
heart. However, ICDs placed in the
vicinity of magnets may temporarily
stop looking for abnormal heart
rhythms.
The bottom line? If your ears
happen to be attached to your chest,
be careful. You may have problems
that extend beyond the annoying
issues of how to hear through your
raincoat and keep your eyeglasses
from falling off. NV
14
January 2009
