Delta-Sigma (DS) Analog-to-Digital Converters are well known
for their innate ability to resolve an analog input signal to very
small LSB voltage ranges. The primarily applications for this
type of product is in the Industrial Process Control market such
as direct transducer interface for pressure, temperature, flow,
weigh scales and force measurement systems. In the Instrumentation
market, the DS converter is particularly well-suited for
portable applications, such as thermometers, gas analyzers and
blood analyzers. At first glance, high resolution doesn’t seem to
be an important specification for these types of applications. To
the contrary, close inspection of these transducer interface
circuits divulge a different story. The sensing element’s output
could be a fairly high voltage (hundreds of mV to several volts),
however, the delta output voltages that represent a change in
temperature, pressure, light, etc., is usually extremely low, submV
or mV.