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EMBEDDED WORLD 2023: ANALOG DESIGN
Design Challenges Shift for Embedded Analog

Systems

By Majeed Ahmad

Embedded processors, aided by analog circuitry, capture audio, video and other real-world signals in a variety of applications.
(Source: Synaptics)

he need for embedded processors to interact with the physical analog circuit into the chip while taking advantage of digital calibra-
world around them is far from new. At the same time, however, tion to mitigate analog non-idealities.
the combo of embedded processors and analog circuitry keeps In this case, a primary challenge is deciding what you can put in a
T reinventing itself to enable new applications, such as renew- system-on-chip and what really needs to remain external. “That is often
able energy, smart audio and the internet of things. a question of signal level and bandwidth,” Gillespie said. “But the answer
It’s exciting to see how embedded processors combined with analog is always changing, particularly with the advent of very high-
circuits enable a wide range of applications, from smart retail and performance CMOS RF circuits that integrate well with digital logic.”
laptop docking stations to automotive dashboards and tiny, unattended Sam Geha, executive vice president of the IoT, compute and
remote monitoring devices. Some trends are quite recent, however, wireless business at Infineon Technologies, acknowledged that the
and they’re changing the way we think about digital-analog system most advanced analog and mixed-signal designs have leveraged
integrations. process technologies spe-
New design challenges emerge when engineers combine analog with Some trends in cifically designed from the
various embedded processors—especially when embedded processors bottom up for optimal analog
designed to work with analog have also evolved over the years to facili- combining embedded performance.
tate greater battery efficiency and lower power consumption. “Those process technol-
processors with analog ogies are not well suited for
ANALOG ON DIGITAL-FRIENDLY NODES are changing the microcontrollers or micropro-
One perennial challenge with embedded analog systems is that prog- cessors due to performance
ress in silicon technology diverges between digital and analog. way we think about and embedded memory
Processors are driving manufacturing process selections toward more digital-analog system limitations,” he said.
advanced nodes that facilitate higher performance and lower supply Geha added that the
voltages, while analog front-end (AFE) circuits often use higher I/O integrations. industry is overcoming this
voltages for better dynamic range. challenge by designing highly
“Ever smaller feature sizes make digital logic faster and cheaper, but capable analog peripherals
at the same time, they are less and less appropriate for analog circuits,” in standard CMOS or CMOS/NVM process technologies. He quoted the
said Dave Gillespie, R&D fellow at Synaptics. “Consequently, some- example of PSoC microcontrollers, which have been “analog heavy”
times a package that looks like a chip from the outside actually has since their inception.
multiple silicon dice inside.” “This simplifies the design of sensor-based systems by delivering a
In fact, that package is internally wired, so one part can be fabbed in scalable and reconfigurable architecture that integrates programmable
a digital-friendly process and the other in an analog-friendly process. AFEs and a signal-processing engine that can calibrate and tune the
That’s one way to deal with the challenge: Simply incorporate the AFE in software,” Geha said.

www.eetimes.eu | MARCH 2023