|
Used to power portable and handheld electronics
of all types, ac adapters–or “wall warts”–have
traditionally been based on inexpensive linear
transformer-based power supplies. While switching
supplies offer significant size, weight, and
efficiency advantages over linears in this
application, until now they have not been as cost
effective. The LinkSwitch LNK501 high-voltage ac/dc
converter IC (see Electronic Products,
Nov. 2002, p. 53) is designed specifically to
replace low-power transformer “bricks” at 0 to
3-W output. Cheap to produce, the universal input
part delivers switcher benefits–smallest size,
lightest weight, superior performance–at equal
or lower system cost. 
Power Integrations'
LinkSwitch LNK501 ac/dc converter IC
The IC's primary high-side placement halves the
number of components (requires only 14
components) in a typical switcher by combining
the primary clamp, IC supply, and feedback. The
chip includes a 700-V MOSFET, PWM controller,
start up, current limiting, and thermal shutdown.
(From $0.50 ea/10,000–4 weeks ARO.)
Power Integrations
Sunnyvale, CA
Steve Miceli 408-414-8821
http://www.powerint.com
There is an expanding need in the life cycle of
modern materials and devices for instruments that
provide low dc measurement along with stimulation
by a voltage source. For example, creating I/V
curves for characterization of semiconductors and
LEDs, or verifying insulation resistance in
pc-board materials requires dedicated scientific
instruments. Electrometers, tera-ohmmeters, and other highly
sensitive dedicated instruments offer solutions,
but are complex, expensive, and not suitable for
industrial environments or fieldwork. In an
environment of very low power, super high speed,
and closely packed architectures, the Model 6487
picoammeter-voltage source provides a significant
cost/performance improvement over separate
dedicated instruments.
Keithley Instruments'Model 6487,
picoammeter-voltage source
Combining current sensitivity near that of an
electrometer with the ease of use and pricing
comparable to a high-performance DMM, the meter
provides voltages as high as 500 V and can
measure currents as low as 20 fA. The
5-1/2-digit instrument's voltage burden of
less than 200 µV allows for highly accurate
measurements in circuits with low source
voltages. A buffer memory allows picoammeter data to be
acquired at 1,000 readings/s. The instrument also
gives direct resistance measurement readouts to 5
x 1016 W .
The unit's voltage source ranges are ±10,
±50, and ±500 Vdc, with a basic
accuracy of ±0.1%. IEEE-488 and RS-232
interfaces are included, as is a PC-based utility
that allows direct export of data into an Excel
application. ($2,995–available now.)
Keithley Instruments
Cleveland, OH
Ellen Modock 440-498-2746
http://www.keithley.com
Three-dimensional displays promise to make solid
design easier, enable new presentation
applications, and in general, reduce the
disparities that exist between the real world and
graphical representations of it. Until now,
however, 3-D imagery has had to accept
significant compromises in perspective and
viewing angle when displayed.
Actuality System's Perspecta,
spatial 3-D platform
The Perspecta spatial 3-D platform (see
Electronic Products, April 2002, p. 47) is
a true 3-D display–a globe-shaped monitor that
displays imagery with a complete 360°
viewing angle without special goggles. In
operation, the Perspecta's image appears as a
virtual 3-D solid suspended within a transparent
globe, allowing multiple users to walk around it
as they simultaneously view and manipulate images
from any angle. The display creates images by projecting
thousands of 2-D images every second onto a
screen that rotates at 730 rpm. The current
version creates 198 “slices” with a resolution of
768 x 768 pixels that refresh at 24 Hz to fill
the volume of the 10-in. spherical display with
approximately 100 million image bits, called
voxels, in 3-bit color.
(From $50,000–12 to 15 weeks ARO.)
Actuality Systems
Burlington, MA
Robert Southard 781-229-7812, ext. 102
http://www.actuality-systems.com
As microcontrollers proliferate in virtually all
applications–the challenge facing designers and
manufacturers has been keeping costs down, while
continuing to increase product functionality.
Targeted at cost-sensitive embedded applications,
the flash-based 8-bit Nitron HCO8 Q-Series
microcontrollers are intended to make it possible
for designers to incorporate the advantages of a
programmable microcontroller into a broader range
of products than ever before. In addition to featuring low cost, the Nitron
devices are offered as providing increased
flexibility in the development and manufacturing
process, as well as reduced time-to-market and
system costs. The parts are available with a free
version of Metrowerks CodeWarrior Development
Studio Special Edition (valued at more than
$2,000), free online technical training modules,
a comprehensive collection of reference designs,
an applications library, a searchable FAQ
database, and broad third-party developer
support.
Motorola Semiconductor's 8-bit Nitron HCO8,
Q-Series microcontrollers
The devices use 1.5 or 4 Kbytes of 0.5-µm
flash memory that boasts programming times of 100
times faster than most embedded flash. A wide
range of on-chip peripheral functions include a
two-channel 16-bit timer system with selectable
capture, compare, and PWM capabilities; system
protectors such as a selectable trip-point
low-voltage inhibit, auto wakeup from the Stop
COP state; and a four-channel 8-bit A/D
converter.
The 2.7 to 5.5-V devices come in 8- and 16-pin
PDIPs, SOICs, or TSSOPs. (From as low as $0.50 to
$0.70 ea/large qty–stock.)
Motorola Semiconductor
Denver, CO
Reader Inquiry Response 800-441-2447
http://www.motorola.com
As gyroscopes are being implemented in a variety
of applications–such as GPS navigation systems
and vehicle stability control–the need for
integration highly increases. Traditionally, a
separate chip has been required to condition and
amplify the sensor signals, and has required
either a completely separate package or a larger
package to house both chips. The iMEMS ADXRS (see Electronic Products,
Dec. 2002, p. 34) is the first commercially
available gyroscope chip to integrate both an
angular rate sensor and signal-processing
electronics onto a single chip–making it
smaller, more accurate, more reliable, and more
economical than other rate sensors in its class.
Measuring only 7 x 7 x 3 mm, the part delivers
stable output in the presence of mechanical noise
up to 2,000 g over a wide frequency range–a
feature important in rollover detection.
The device is built using the company's
integrated microelectromechanical system (iMEMS)
surface-micromachining process and consumes 30 mW
from a 5-V supply. Two versions are available:
The ADXRS300 offers a dynamic range of
300°/s, and the ADXRS150 offers 150°/s.
($30 ea/1,000–available now.)
Analog Devices
Wilmington, MA
Information 617-761-7313
http://www.analog.com
Toroidal transformer cores have long been
recognized for their superior performance to EI
or CI cores in terms of efficiency and emitted
fields. Wound from a single strip of
grain-oriented silicon steel, toroidal cores are
usually insulated with fluidized epoxy or covered
with injection-molded caps to protect the
windings from the strip's sharp edges. Moreover,
the traditional toroidal core's rectangular
cross-section results in greater stress on the
windings and winding machine during manufacture. The O-Core toroidal core solves these problems by
using a strip that is laser-cut with a gradual
taper from the center to each end–resulting in a
circular cross-section. Compared with traditional
cores of similar ratings, weight is reduced by
30% and size by 15% with no sharp edges; two
layers of Mylar tape are sufficient insulation. 
Alpha-Core's O-Core
toroidal transformer core Heavier wire can be wound at lower tensions,
resulting in a greater fill factor at the core's
inner diameter “window.” Those improvements, as
well as using less copper per turn for a greater
copper/steel ratio, result in transformers that
can reach efficiencies of 98% compared with the
typical 95% of rectangular toroids.
Features include VA ratings from 12 to 1,200 at
60 Hz, weights from 0.57 to 10.65 lb, and sizes
from 1.26 (i.d.) x 2.52 (o.d.) x 0.65 to 2.95
(i.d.) x 6.54 (o.d.) x 1.85 in. (From
$1.68–available now.)
Alpha-Core
Bridgeport, CT
Ulrik Poulsen 203-335-6805
http://www.alphacore.com
While GPS capability is being added to an
ever-expanding array of products, power and size
issues have been roadblocks preventing its use in
the smallest handheld products like PDAs and cell
phones. Traditional GPS modules employed in
conventional handheld products measure about 25
cm3 and weigh 25 g, making them
unsuitable for lightweight and power-stingy PDAs
and cell phones.
SiGe Semiconductor's PointCharger,
SE4100 GPS receiver IC
Introduced last September, the PointCharger
SE4100 GPS receiver IC was offered as the first
such device to address these issues (see
Electronic Products, Dec. 2002, p. 46).
The device uses SiGe process technology to
provide a power consumption of only 10 mA. A
system consisting of the IC paired with many
leading baseband circuits consumes less than 120
mW in continuous operation.
Other features include a high-performance LNA and
a very low external component count–allowing it
to be cost effectively implemented in portable
devices where the GPS antenna is in the same
enclosure. ($3.50 ea/10,000–samples available
now.)
SiGe Semiconductor
Ottawa, Ontario, Canada
Bev Hemish 613-820-9244
Fax 613-820-4933
http://www.sige.com
The progression of light-emitting diode
technology has been one of continually shorter
wavelength emission, with the first LEDs emitting
red or amber light, and the shorter wavelengths
such as green and blue following only recently.
The importance of having the full spectrum of
light available is apparent in applications such
as RGB color display and incandescent bulb
replacement, among others. The Megabright Series UV LEDs (Electronic
Products, Jan. 2002, p. 54) are the first to
achieve emission at 395 and 405 nm, and at the
time of their introduction were the brightest
nitride-based LEDs available. The 12-mW devices
provide distinct benefits over incandescent UV
technology due to longer operational time and
increased energy efficiency. The LEDs can also convert their emissions to
white light by passing the UV through a phosphor
or other polymer material. This approach provides
better color rendering, manufacturability, color
temperature, and control over alternative methods
using blue LEDs with a yellow phosphor.
(From $0.50 ea/10,000–available now.)
Cree
Durham, NC
Mike Dunn 919-313-5508
http://www.cree.com
The engineering need for oscillators to be more
flexible continues to grow. With many
applications–such as CATV, adaptable networks,
wireless hubs, and cellular base stations–using
multiple oscillators on one board, engineers are
increasingly requiring the flexibility to change
frequencies in-circuit on the fly. The MIPO multifrequency in-circuit reconfigurable
programmable oscillators were introduced this
past September (see Electronic Products,
Sept. 2002, p. 74) as the first of their kind to
address this need. The parts can be reconfigured
in-circuit an infinite number of times using the
I2 C interface–a feature never before
available in a quartz timing product. 
Cardinal Components'
MIPO oscillators In addition, the oscillators consume less than
50% of the power of traditional devices, while
reducing board space by 30% and component count
from six to one. Operating from a 3.3-V supply,
the family has a frequency range from 200-kHz to
200-MHz CMOS and 100 to 400-MHz PECL.
(Less than $6 ea/prod qty–available now.)
Cardinal Components
Wayne, NJ
James Magos 973-785-1333, ext. 505
http://www.cardinalxtal.com
Enclosure manufacturers, increasingly challenged
with fitting more and more components into the
same or less space, are basically bound by the
physical constraints of length times width times
height. Incorporating a unique modular design
based on interchangeable latches, posts, hinges,
and panels, the DiamondShield Fiberglass
Enclosures (see Electronic Products, May
2002, p. 56) are offered as the only enclosures
in the industry to enable every cubic inch of
interior volume to be used.
Stahlin's DiamondShield,
Fiberglass Enclosures
The company's “no-limits” panel management system
allows panels of any size to be mounted at any
height or depth, and hinged in any direction
within the enclosure, as well as on the door,
providing designers with 25% to 30% more usable
surface area than standard enclosures of the same
type. Available in 10 sizes from 6 x 6 x 4 in. to
20 x 16 x 10 in., more than 150 off-the-shelf and
custom configurations are possible.
Formed by compression molding processes, the
enclosures can be shielded against RFI/EFI. More
than 20 standard colors and graphic interfaces
are available, including silk-screening and
decals. (From $35–available now.)
Stahlin
Belding, MI
Tami McNee 616-794-0700
http://www.stahlin.com
There were significant evolutionary changes in
power systems technology in 2002, but only one
revolutionary development. The Wire-Free
Electricity Base system (Electronic
Products, Dec. 2002, p. 39) may completely
change the way portable devices can be charged,
and promises to completely separate the charger
from the device in the mind (and actions) of the
user. Providing a replacement for plug-in power
adapters, the wire-free portable-device power
system can drive and charge any compatible device
placed on its desk-blotter-style mat–freeing the
user from cables, adapters, and the bulk and
complexity involved. The system can safely power
multiple items of up to 30 V each simultaneously
with a total power requirement of up to 240 W 
MobileWise's Wire-Free
Electricity Base. The system features a control chipset that is
placed into the contact mat and an adapter chip,
called the Wire-Free Electricity Adapter, which
resides inside compatible portable devices.
The Wire-Free Electricity Base meets relevant EMC
and safety requirements, and can be retrofitted
to existing devices using an external coin-sized
adapter. (Base station chipset, from $3;
device-side chip, from $1–available now.)
MobileWise
Los Altos, CA
Information 650-938-6352
http://www.mobilewise.com
Of the communications technologies moving toward
3G functionality, GSM is the growth leader,
representing 67% of the world's wireless
market–although lagging a distant fourth in U.S.
sales. Supported by a packet-based GPRS
enhancement and in-place satellite roaming,
GSM-based products introduced into the American
market promise to give this communications
standard a truly global reach. The P3100-series WISMO Pac module combines
several innovations that give PDA and cell phone
designers a complete and fully integrated
dual-band GSM/GPRS solution in a 1.77 x 1.28 x
0.20-in. package. The 0.39-oz device combines
shielding, mounting, and connectivity in a single
element that can be automatically positioned and
soldered onto a circuit board like any regular
IC.
Wavecom's WISMO Pac,
GSM/GPRS module
Powered by 3.6 Vdc, the 222-pin component draws
300 mA average current during communication and
less than 3.5 mA in idle mode. It also features a
variety of interfaces including general-purpose
I/Os, RS-232, an LCD parallel bus, and support
for IrDA.
The WISMO Pac series includes 900/1,800- and
900/1,900-MHz versions with either 16/2- or
32/4-Mbytes of memory. Used by Handspring as a
core enabler of its Treo line of communicators,
the device integrates mobile calling, wireless
e-mail, messaging, and full Web browsing. (Around
$59–available now.)
Wavecom
Issy-les-Moulineaux, France
Mette Gullesen 0-11-33-146-299-756
Fax 0-11-33-146-290-808
http://www.wavecom.com
Sometimes an advance in the industry is
represented by devices at the lower end of the
scale, demonstrating the depth of acceptance of a
technology. Every top-shelf, proof-of-concept,
hand-built, money-is-no-object device has to be
followed by mainstream bread-and-butter products,
or the technology is next to useless. The DPLED1602 OLED display module represents the
first instance of an off-the-shelf OLED product
designed for broad application in existing
devices–the vanguard of a flood of OLED products
that promises to eventually displace other
display technologies for many applications.
Designed as a drop-in replacement for LCD units,
the 2 x 16-character display communicates via an
8-bit parallel interface and is broadly
compatible with standard LCD controllers. 
Densitron's DPLED1602
OLED display The device enables engineers to upgrade existing
devices from an LCD to an OLED display with
minimal redesign. Consuming 20 mA for a
brightness of 40 nits, the module employs a thin
layer of organic electroluminescent material
sandwiched between a pair of electrodes, creating
a high-brightness display that requires no
backlight.
Specifications include a contrast ratio of
100:1–up to 20 times greater than an LCD–and a
viewing angle that exceeds 160°–up to twice
that of an LCD. The display has an active area of
56.15 x 11.4 mm, a pixel size of 0.5 x 0.6 mm,
and a pixel pitch of 0.6 x 0.7 mm. (From less
than $10 ea/1,000–stock to 10 weeks ARO.)
Densitron
Santa Fe Springs, CA
Jason O'Rourke 562-941-5000
http://www.densitron.com
Nothingcan beat tantalum as the material of
choice for temperature stability and leakage
current. Unfortunately, tantalum ore is in short
supply, causing prices and availability to be
uncertain at best. Niobium, with its greater dielectric constant and
abundant supply, has long been a candidate to
substitute for tantalum. However, the material's
poor thermal stability makes building niobium
capacitors difficult, and its higher voltage
constant makes for an inferior capacitor when
compared with tantalum. Last year, several manufacturers redoubled their
efforts in manufacturing techniques and
applications of materials science to turn niobium
devices into drop-in replacements for tantalum
products. Although Vishay Intertechnology was
first to announce the availability of laboratory
samples of its 910D Series (see Electronic
Products, Nov. 2001, p. 26), the B75194 and
B75196 Series from EPCOS (see Electronic
Products, May 2002, p. 51) were the first to
be available in production quantities.
Specifications for the 7343-packaged 910D Series
include values between 10 and 680 µF with a
20% tolerance and voltage ratings between 6 and
16 V. The B75194 and B75196 Series has values
between 68 and 330 µF and working voltages
of 6.3 and 10 V. (EPCOS B75194 and B75196 Series,
from $0.05 ea/prod qty–available now.)
EPCOS
Iselin, NJ
Michael Pocsatko 800-888-7729
Fax 732-632-2830
http://www.usa.epcos.com
Vishay Intertechnology, Malvern, PA
Andrew Post 610-251-5287
Fax 610-889-9429
http://www.vishay.com
Finding increased use in power semiconductors,
silicon-carbide (SiC) technology–a recent
alternative to traditional silicon
technology–provides high-voltage, high-current,
and high-temperature capabilities while providing
lower switching losses and higher switching
frequencies. Although SiC devices can operate at
temperatures of 500° to 800°C, current
packaging limits temperatures to 125° to
175°C. The SSR05C60 Series SiC power Schottky diodes
(see Electronic Products, Dec. 2002, p.
48) break that limitation by using a hermetic
package, allowing a temperature limit of
300°C with zero switching losses. The
devices can be used not only in extreme
environments, such as aerospace applications, but
as drop-in replacements for current silicon
technology.
The devices' thermal conductivity–three times
that of Si and 10 times that of GaAs
devices–eliminates or greatly reduces the need
for excessive heat sinking or active cooling
methods such as forced-air cooling or
liquid-based solutions, reducing design
complexity and increasing reliability. (From $20
ea/small qty–available now.)
Solid State Devices
La Mirada, CA
Sales 562-404-4474, ext. 234
http://www.ssdi-power.com
Sensing ambient light to control display
backlights on portable devices such as PDAs, cell
phones, and notebook computers makes displays
easier to read under varying light levels as well
as saves power by reducing backlighting to
acceptable levels without sacrificing
readability. However, traditional sensing
techniques do not take into account how the human
eye perceives light from different sources, such
as incandescent, fluorescent, and natural
sunlight. Such light sources have widely different spectrum
content. A particular display intensity might be
easy to read under incandescent light, but
difficult to read under fluorescent light or
sunlight. 
Texas Advanced Optoelectronic Solutions'
TSL2550 ambient light sensor
The TSL2550 ambient light sensor (see
Electronic Products, Nov. 2002, p. 68) is
offered as the industry's first such device that
mimics the human eye's light response without
requiring expensive photoptic filters. The device
provides digitized values from two
photodetectors–one for visible and infrared
light, the other for infrared light only. The
ratio between the sensor outputs can determine
the type of ambient light and its intensity, for
more accurate control of display contrast and
brightness. (From $1.36 ea/1,000–available now.)
Texas Advanced Optoelectronic Solutions
Plano, TX
Sales 972-673-0759
http://www.taosinc.com
As next-generation microprocessors demand more
power–20 A per phase or higher–from
smaller-packaged dc/dc converters, power supply
designers are increasingly faced with heat
dissipation issues. Although advances in power
MOSFET silicon are helping to address these
issues, semiconductor packaging has become a
limiting factor. While semiconductor packages typically remove
heat through the bottom, the IRF660x DirectFET
MOSFET (see Electronic Products, May 2002,
p. 52) enables heat to be dissipated through both
the top and bottom when used with appropriate
heat sinks, doubling heat removal compared with
standard designs that remove heat via only the
bottom. The 0.7-mm-high SO-8-compatible package contains
the silicon die into a copper housing that acts
as a drain connection from the topside to the
board. That, coupled with large-area contacts on
the package's underside that solder directly to
the board, helps to reduce junction-to-pc-board
thermal resistance to 1°C/W compared with
20°C/W from a standard SO-8 plastic-molded
package.
Junction-to-case thermal resistance is lowered to
3°C/W using the DirectFET packaging compared
with 18°C/W using the SO-8 package. (From
$0.77 ea/10,000–available now.)
International Rectifier
El Segundo, CA
Joe Engle 310-252-7019
http://www.irf.com
|
