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.
Why measure temperature?
Temperature impacts virtually every application and system design, from insuring safe operations, to optimizing process controls or calibrating other sensors.
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
Temperature sensors can monitor the temperature of the system and take appropriate action. Examples:
- Optimizing fan speed
- HVAC & thermostats
- Industrial control
- Modulating system performance
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
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)
Standard silicon process:
- Economies of scale