62 l New-Tech Magazine Europe
ne company in Austin, Texas
is about to change the way
electronics are powered.
The Internet of Things and the
advent of ubiquitous computing
have highlighted the importance
of reducing power consumption
throughout electronics.
If the immediate future will truly see
the networking of all electronics and
hitherto unconnected devices then
the real prize is not to maximise
the performance of the technology
- the performance is fast enough
to maintain an IoT already - it is to
reduce energy consumption enough
that the electronic things can function
meaningfully within this new internet.
Energy is consumed in two
fundamental ways: as leakage, when
a circuit’s state isn’t changing, and
dynamically as internal nodes are
charged up and down. For realistic
circuits in operation, dynamic power
dominates - especially for the higher
power supply voltages used in most
designs today (see Figure 1).
Dynamic energy is
determined by operating
voltage
Sub-threshold techniques are a
way to create circuits that consume
dramatically less energy than those
built using standard design practices.
Sub-threshold design is challenging,
but, given the right experience and
diligence, it can be done and with
immense benefits.
The results are circuits that provide
the same functions as more
traditional ones but use a fraction of
the energy. There is no compromise in
performance, robustness, or reliability.
These chips can operate alongside
their traditional counterparts with no
externally-visible difference – except
for the amount of energy required
to drive them. They can provide
important energy savings to designers
building energy-efficient systems.
Because of the fundamental nature
of these innovations, sub-threshold
design techniques can be applied to
virtually any type of IC device.
Sub-threshold was proven
decades ago
Sub-threshold design isn’t a new
concept. As far back as the 1970s,
O
A Revolutionary Approach to
Eliminating Power
Mike Salas, Ambiq Micro