require little power and operate only
intermittently. It may have a battery or
an energy harvesting feature to deliver
short bursts of power when the device is
awake for a timed event that occurs at
regular intervals or for one instigated by a
user (e.g., reading a sensor and displaying
the results) before returning to a waiting
mode. This ultralow current consumption
in the operating and idle states means
the system can function longer with
smaller batteries.
FPGAs add complexity
Another inherent complexity arises
from the reconfigurability and re-
programmability of FPGAs. Finding the
optimum power management solution for
FPGAs usually requires additional voltage
rails and loads that also need to be
powered, and the input power of FPGAs
is not fixed. The input voltage heavily
depends on the actual logic levels and the
design that the FPGA is implementing.
The current consumption of any FPGA
depends heavily on the use case, many of
which can influence power requirements.
At the low end, FPGAs are used in
digital signal processing, biomedical
instrumentation, and medical imaging.
Higher-end applications are usually
found in the data center for hardware
acceleration and enterprise networking,
as well as in automotive advanced driver
assistance systems, where availability and
reliability are essential.
Several types of low-end and high-end
devices exist within the three categories
of microcontrollers, processors, and
FPGAs, all of which influence power
management choices within the broader
system as power supplies have had to
adapt, which means higher efficiency and
capabilities for different voltage rails.
And because electrification is
driving trends in power management,
microcontrollers, processors, and FPGAs
C h a p t e r 1 | W h a t I s P o w e r M a n a g e m e n t ?
Efficient cooling solutions are
essential to avoid excessive power
consumption. This includes using
advanced heatsinks, optimizing
airflow, and exploring options like
liquid cooling."
Pragun Khanduja
Hardware Engineer II, Cisco
8
Power Management: Efficiently Powering Processors, FPGAs, and Microcontrollers
