Watch for analog *sound* technologies to reappear!
Wired 11.03: Start
[snipped all but this]
Why Analog Is Cool Again
Super-sensitive switches etched in silicon? This is not your father's
By Paul Boutin
Sharp, vibrant, incredibly detailed: The pictures produced by Foveon's
X3 image sensor chip are seductive evidence that pixels will displace
film. The Sigma SD9 - the first commercial camera to use Foveon's
technology - captures three times more color per pixel than standard
digital shooters. But here's the thing: This isn't digital technology.
It's a twist on old-fashioned analog electronics - an array of
millions of light filters and detectors etched in silicon.
Weird as it sounds, the road to smaller, cheaper, more
energy-efficient consumer electronics may be paved with analog
technology. These circuits are built from the same components as their
digital counterparts but suck 90 percent less battery power. The
difference? In an analog device, each transistor acts like a dial,
with a wide range of readings that depend on the sinuous fluctuation
of voltage, current, amplitude, and frequency. Digital circuits, on
the other hand, use the same transistors as simple on-off toggle
switches. Analog transistors capture far more information, so you need
fewer of them.
Advances in the digital realm are powering the technology. Tiny analog
circuits, sensors, and even radios can be manufactured using the same
fabrication techniques - microscopic etching on semiconductor wafers -
that have kept Moore's law chugging along. Devices with analog chips
in their guts will begin landing in consumers' hands this year in the
form of high resolution cameras and mobile phones that can go a week
Much of the new analog circuitry creeping into consumer gadgets
springs from the research of Carver Mead, Foveon's founder and chair.
As a Caltech professor (now emeritus) in the 1970s, Mead sought to
imitate the analog elegance of the human brain. In 1986, Mead
cofounded a company, Synaptics, to build high-performance analog
computers. He understood that solid state circuitry would be ideal for
connecting computers to the real world of light, touch, and sound,
which are analog by nature. Synaptics eventually focused on the
tactile, becoming the leader in laptop touchpads. (It controls about
80 percent of that market.)
Next came Foveon, founded in 1997. Its X3 image sensor chip is perhaps
the most impressive analog electronics application so far. Standard
digital cameras use filters that permit light sensors to capture only
one primary color per pixel. From there, a signal processor runs
algorithms that approximate the missing colors by sampling nearby
pixels. That guessing game introduces telltale lines and whorls into
the final picture. Foveon found a way to use standard silicon as an
analog color separator. One of the optical properties of silicon is
that different wavelengths of light penetrate it to different depths.
This allows Foveon chips to stack red, green, and blue sensors at
Impinj, another Mead startup, hopes to conquer sound with a technology
that lets digital logic fine-tune a cell phone's analog transmitter
midcall, so the overall circuit can be smaller. Impinj claims the
design draws one-tenth the power of its two-part predecessors. It also
puts out a more efficient signal, allowing phone networks to carry
greater call volume. It costs less, too.
For Foveon chief scientist Dick Lyon, who toiled for decades in the
shadow of the Digital Revolution, there's a sweet payback to sculpting
analog parts from silicon: "If you do it right, you can make
transistors and create devices no one imagined."
Paul Boutin ([log in to unmask]) wrote about CD-R swapping in Wired