Sensing Products

Fundamentals

Fundamentals of IC temperature sensors

TI is the world’s largest manufacturer of silicon temperature sensors. From creating the world’s first IC over 40 years ago to today, TI continuously revolutionizes temperature measurement with higher accuracies, lower power, smaller packages, and greater integration & features.

Fundamentals of temperature sensors

Why measure temperature?

Temperature impacts virtually every application and system design, from insuring safe operations, to optimizing process controls or calibrating other sensors.

Protection

Protection

Temperature sensors can provide instant notification of when a system has crossed a thermal limit to prevent damage or maintain safety. Examples:

  • Motor control
  • Lighting and signage
  • USB chargers
  • Batteries charging
  • Perishable goods
  • Computing
  • Automotive

Monitor/Control

Temperature sensors can monitor the temperature of the system and take appropriate action. Examples:

  • Optimizing fan speed
  • HVAC & thermostats
  • Industrial control
  • Modulating system performance
  • Automotive
Calibration

Calibration

Temperature sensors can be used to calibrate other temperature sensitive sensors or system components. Examples:

  • Gas and flow meters
  • CMOS image sensors
  • LED color correction and backlighting
  • Optical and ultrasonic position sensors
  • Automotive

How an IC temperature sensor works

 

IC temperature sensors are based upon the highly predictable thermal characteristics of a transistor PN junction. Precision current sources forward bias an internal PN junction with the resulting DVBE corresponding to the device’s temperature.

Principle of operation

IC sensors leverage the highly predictable thermal characteristics of a silicon PN junction.

Advantages of using an IC temperature sensor

• Accuracy is guaranteed across a broad temperature range (-55°C to 200°C)

  • Zero calibration
  • Highly linear
  • Low noise sensitivity

• Low power (<2.5uW possible with integrated ADC)

• Compact packaging options (down to 0.64mm2 footprint)

• Fast response

• Standard silicon process

  • Economies of scale
  • Reliability
  • Integration