"Each device has its own
set of requirements.
Whereas some devices
require wide bandwidth,
others need rapid
response times to perform
their functions best."
Nishith Patel
Principal Hardware Engineer,
ABB GISPL
Chapter Four
Optimizing for Highest Precision
with Fast Sampling
In other scenarios, engineers might wish to design a precision signal chain for fast sampling or
wide bandwidth applications.
An example of an application that requires high precision with fast sampling is any closed-loop
feedback system, such as hardware-in-the-loop or a source measurement function used in test
and measurement instruments. In a system like this, feedback from the output is used as an input,
and this information informs the system's decision-making to produce a more precise system. In
this case, the latency of the signal chain will contribute to the latency of the whole system—for the
best performance, engineers need signal chains that achieve the fastest sampling rate possible, all
without sacrificing precision.
One aspect of achieving a precision wide bandwidth signal chain is the use of specialized high-
precision, fast components such as high-resolution ADCs and DACs featuring high sampling rates.
However, for truly fast performance, the chain must be considered holistically, requiring a fast
analog front end, filtering stages, and programmable gain stages.
Beyond just component selection, other aspects of system design become crucial. For example,
as speeds increase, clock jitter can become a limiting factor in a system's performance. Another
factor for achieving high precision at fast sampling is the system layout. Good practices such as
separating digital and analog systems can have a significant impact on the performance of wide
bandwidth signal chains. Tools like LTspice® enable engineers to analyze signal chain noise and
transient performance in a simulation environment.
17 | Optimizing for Highest Precision with Fast Sampling
