Specifications

Sensors
Temperature sensing
68 Maxim Industrial Solutions
Overview
Temperature sensing is critically
important for implementing three
key functions in industrial systems.
1. Temperature control, for
example in ovens, refrigeration,
and environmental-control
systems, depends on the
measurement of temperature to
make heating/cooling decisions.
2. Calibration of a variety of
transducers, oscillators, and
other components often varies
with temperature. Therefore,
temperature must be measured
to ensure the accuracy of sensitive
system components.
3. Protection of components and
systems from damaging temper-
ature excursions. Temperature
sensing determines the appro-
priate action to take.
Thermistors, RTDs, thermocouples,
and ICs are some of today’s most
widely used temperature-sensing
technologies. Each design approach
has its own strengths (e.g., cost,
accuracy, temperature range) which
make it appropriate for specific appli-
cations. Each of these technologies
will be discussed below.
In addition to the industry’s most
comprehensive line of dedicated
temperature-sensor ICs, Maxim
manufactures all of the compo-
nents necessary to interface a
system to thermistors, RTDs, and
thermocouples.
Temperature sensing
EXCITATION
μC
SENSOR AND
NETWORK
AFE FILTER ADC DIGITAL DOMAIN
ADC
Reference
DAC
REF
TEMP
SENSORS
THERMISTOR
THERMOCOUPLE
PGA
IA
REFERENCE
LEVEL
TRANSLATOR
TOUCH
SCREEN
ISOLATION
ADC
OP AMPS
DIGITAL
POTENTIOMETERS
PRECISION
RESISTORS
V
RTD
= MAXIM SOLUTION
Block diagram of the signal chain in a temperature-sensing application. For a list of Maxim’s recommended temperature-sensor solutions, please go to: www.maxim-ic.com/-40+85.