IEEE Solid-State Circuits Magazine - Winter 2018 - 31

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share information. These social technologies allow people to maintain
connections and support networks
not otherwise possible; they provide
the ability to access information
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The ISSCC covers a spectrum of
design approaches in various technical areas, which may be broadly categorized as analog systems, power
management, analog-to-digital data
conversion, communication systems,
digital systems, and memory, along
with innovative topics such as micromachines and microelectromechanical systems (MEMS), imagers,
sensors, and biomedical devices,
including forward-looking solutions
that may be several years away from
being commercialized.

The 11 ISSCC technical subcommittees annually update their analysis of industry trends for the benefit
of the community at large. This article summarizes some of these views
in selected technical areas. A more
comprehensive trends document is
available at www.isscc.org.

tions, while still maintaining (or even
improving) power efficiency.

Analog Systems: Analog

While the manipulation and storage of
information are efficiently performed
digitally, the conversion and storage of
energy are fundamentally performed
with analog systems. The efficient
control, storage, and distribution of
energy are worldwide challenges and
increasingly important areas for analog circuit research. Therefore, the
key technologies for power management are predominantly analog.
For example, there is much interest in wireless power transmission for
battery-charging applications, ranging from mobile handsets to medical implants. Increased performance
in wireless power transmission is
enabling more efficient power delivery over longer distances. There is
also an explosion of technologies that
allow energy to be collected from the
environment in novel ways using
photovoltaic, piezoelectric, or thermoelectric transducers, with a trend
toward the use of multiple sources
at the same time. A significant focus
here is on analog circuits that can harvest submicrowatt power levels from
multiple energy sources at tens of
millivolts and so provide autonomy
for IoE devices or supplement conventional battery supplies in portable
devices. To achieve this, the attendant analog circuits must consume
extremely low power so that surplus
energy is available to charge a battery or supercapacitor. This trend is
captured by the movement shown
toward the top left of Figure 3.
Analog circuits also serve as a
bridge between the digital and analog (real) worlds. Just as with actual
bridges, analog circuits are often bottlenecks, and their design is critical to
overall performance, efficiency, and
robustness. In spite of this, digital circuits such as microprocessors have

Subcommittee Chair: Kofi A.A.
Makinwa, Delft University of
Technology, The Netherlands
Reduction in the energy consumption of analog systems-including
sensors, amplifiers, and voltage and
frequency references-has continued
making gains to meet the demands
of today's low-power systems. This
trend is captured, for example, in the
case of integrated temperature sensors by the movement toward the bottom right of the plot shown in Figure 1.
Fast power-up and power-down of such
systems are also necessary to facilitate
the use of duty-cycling and achieve
even higher energy efficiencies. Together, these trends portend a future
in which portable devices can be powered indefinitely from sustainable
sources, opening the door to the Internet of Everything (IoE), ubiquitous
sensing, environmental monitoring,
and medical applications.
The stringent clocking requirements of many types of batterypowered mobile and emerging IoE
systems pose various challenges for
system-level frequency references,
including increased frequency stability, low noise, and strict temperature-coefficient (TC) control with
a limited energy budget. To meet
these challenges, the stability of integrated frequency references has
been increasing steadily, as shown
in Figure 2. This year at ISSCC 2018,
a 7-MHz complementary-metal-oxide-semiconductor (CMOS) frequency reference is being demonstrated
to achieve a TC of 3.85 ppm/˚C, the
lowest reported so far.
We also see an increase in the linearity and resolution of amplifiers
for audio and precision amplifica-

Analog Systems:
Power Management
Subcommittee Chair:
Axel Thomsen, Cirrus Logic,
Austin, Texas

IEEE SOLID-STATE CIRCUITS MAGAZINE

W I n t E r 2 0 18

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Table of Contents for the Digital Edition of IEEE Solid-State Circuits Magazine - Winter 2018