IEEE Solid-States Circuits Magazine - Winter 2022 - 55

Furthermore, new technologies are
providing opportunities to develop
innovative circuits, reduce fabrication
impacts, and improve recyclability.
ISSCC covers a spectrum of design
approaches in various technical areas
and advances, broadly categorized as
analog systems, power management,
analog-to-digital data conversion,
communication systems, digital systems
[including machine learning
and artificial intelligence (AI)], and
memory. It also covers innovative
topics, such as imagers, sensors,
quantum technologies, and biomedical
devices, including forward-looking
solutions that may be several
years from commercialization. The
12 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.
Analog Systems
Subcommittee Chair: Maurits
Ortmanns, University of Ulm
Institute of Microelectronics, Ulm,
Baden-Württemberg, Germany
At ISSCC 2022, the drive remains
strong to develop new analog circuit
techniques for pushing the performance
of frequency references, sensor
interfaces (temperature, electric
current, magnetic field, and mass
flow), high-speed comparators, and
audio amplifiers. The temperature
stability of RC frequency references
continues to improve, as shown in
Figure 1. By intermittently referencing
the XO in a single XO-based clock
management system, an on-chip RC oscillator
at ISSCC 2022 attains the best
stability ever revealed (0.68 ppm/°C)
using a duty-cycled, machine learningbased
calibration scheme.
In other applications, a new bipolar
junction transistor-based
CMOS temperature sensor achieves a
±0.45 °C ()3v inaccuracy using onepoint
trim across a wide temperature
range, from -50 to 180 °C, without
sacrificing energy efficiency at high
temperatures (.
97pJ K2
$ at room temTo
cope with strong environmental changes, the
circuit design community is evolving more than
ever to support a more sustainable world.
perature and 72 . pJ$K2
at 150 °C). A
high-performance comparator now
features 174Vrmsninput-referred
noise
and a sub-500-ps clock-out delay
while consuming only 75 fJ per
comparison, supporting the development
of efficient gigabit-per-second
serial communication as well as
5G/6G baseband applications.
Significant advancements are
shown in audio amplifiers, regarding
a wider dynamic range, power reduc1,000
10,000
100,000
100
10
0.1
1
2008
2010 2012 2014 2016 2018 2020 2022
Year
FIGURE 1: The trends in stability through time for noncrystal oscillators. VLSI: IEEE VLSI
Symposium on Technology and Circuits; CICC: IEEE Custom Integrated Circuits Conference.
120
110
100
90
80
70
60
50
90
tion, and improved linearity, as illustrated
in Figure 2. The design of class
D amplifiers has matured so much
that the fundamental limits for noise
are coming in range, and new creative
solutions are needed to go beyond
them. This is addressed in this
year's papers, using techniques such
as supply voltage-scaling volume
control, dual voltage/current feedback,
and the first capacitive gain
chopper, class D audio amplifier.
ISSCC
CICC
VLSI
ESSCIRC
ASSCC ISSCC2022
ASSCC ISSCC202
2005-2021 ISSCC/VLSIC
2022 ISSCC
95 100 105 110 115 120 125
SNR (dB) (A-Weighted)
FIGURE 2: The trends in class D amplifier performance. dBc: decibels relative to the
carrier; SNR: signal-to-noise ratio.
IEEE SOLID-STATE CIRCUITS MAGAZINE WINTER 2022
55
THD+N (dBc)
Stability (ppm/° C)

IEEE Solid-States Circuits Magazine - Winter 2022

Table of Contents for the Digital Edition of IEEE Solid-States Circuits Magazine - Winter 2022