Six Technologies that Save Smartphone Batteries

These six new technologies are interesting approaches for cutting down the power used during battery operation.
Some of the technologies, such as operating near the threshold voltage, would be difficult to manufacture consistently in the fab with reasonable yield.

Ron Maltiel



Six Paths to Six Technologies that Save Smartphone Batteries
http://spectrum.ieee.org/semiconductors/processors/six-paths-to-longer-battery-life#.T3Wwc8D6prE.twitter
By Rachel Courtland / April 2012

The boom in mobile devices and data centers has circuit designers
racing to find new ways to slash power consumption. At this year's
International Solid-State Circuits Conference, in San Francisco, six
power-saving technologies took center stage. Some will emerge in
products this year, while others are just beginning to catch the
interest of major chipmakers.rigueur for today's processors—all the
way down to 280 millivolts. The chip's sweet spot for energy
efficiency was 450 mV, just above the threshold voltage. At that
level, Intel's chip ran slowly, at less than 100 megahertz, but it
also consumed just about a fifth of the energy it did at 1.2 V.
Parallel processing could be used to pick up some of the slack in
performance.Mudd College, in Claremont, Calif., showed that the
approach works on an ARM Cortex-M3 processor, boosting energy
efficiency by 60 percent. The team says it's the first implementation
of a Razor-style scheme on a complete commercial processor. nm Ivy
Bridge chips can be run just as fast as the company's previous chips,
but with an operating voltage that's 200 mV lower. Intel has also
incorporated designs at the circuit and core level to improve the
chip's power management. A separate system-on-a-chip code-named
Silvermont, based on the same transistor-making process, will be
geared for mobile handsets. Samsung presented a new improvement on the
all-digital phase-locked loop, a 0.012-square-millimeter circuit that
consumes just 2.5 mW. Intel showed off a version of the circuit, built
with the company's 22-nm technology, that consumes as little as 0.7
mW.Chiao Tung University, in Hsinchu, Taiwan, found a way to save
power by working on signals in two separate stages—one for crude
processing and the other for fine-tuning—that can each be
optimized.Samsung and Hynix Semiconductor both unveiled details on the
next incarnation of synchronous DRAM, the memory that drives today's
processors. The new generation, which goes by the name DDR4, boasts
circuit tricks that let Samsung drop the supply voltage to its memory
modules from 1.5 V to 1.2 V. The modules also include better clocking
and faster algorithms for encoding data to be sent to and fetched from
memory. DDR4 may make its commercial debut as early as 2013.