NXP KTY83-110 Silicon Temperature Sensor: Operation, Features, and Application Circuit Design
The NXP KTY83-110 is a highly reliable silicon-based temperature sensor renowned for its excellent linearity, robustness, and ease of integration into a wide range of electronic systems. Operating on the principle of the positive temperature coefficient (PTC) of silicon, its resistance increases predictably with rising temperature, making it a preferred choice for precision temperature measurement and control.
Operation Principle
The core operating principle of the KTY83-110 leverages the well-defined behavior of doped silicon. As the temperature rises, the number of charge carriers increases, leading to a predictable increase in its electrical resistance. This relationship between temperature and resistance is highly linear, which greatly simplifies the conversion of the measured resistance into an accurate temperature reading. The sensor typically operates over a temperature range of -55°C to +150°C, covering the requirements of most industrial, automotive, and consumer applications.
Key Features
The KTY83-110 stands out due to several distinctive features:
High Linearity: Its nearly linear resistance-temperature characteristic minimizes the need for complex signal conditioning and calibration.
Wide Operating Range: Suitable for both sub-zero and high-temperature environments.
Robustness and Long-Term Stability: Built with silicon technology, it offers high reliability and stability over time, even in harsh conditions.
Two-Lead Configuration: Its simple two-terminal design functions like a precision PTC thermistor, making it easy to interface with standard measurement circuits.
Inherently Linear Output: The output signal (resistance) is a direct and linear function of temperature, unlike the exponential response of NTC thermistors.
Application Circuit Design
Designing a circuit with the KTY83-110 is straightforward. The most common method is to use the sensor in a voltage divider configuration. The sensor (R_sensor) is connected in series with a precision reference resistor (R_ref) across a stable voltage supply (V_supply). The output voltage (V_out) taken from the junction of the two resistors is fed to an analog-to-digital converter (ADC) of a microcontroller.
The output voltage is given by: V_out = V_supply (R_sensor / (R_ref + R_sensor))
As temperature changes, R_sensor changes, causing a proportional change in V_out. The value of R_ref is typically chosen to be close to the sensor's nominal resistance at the middle of the desired temperature range (e.g., ~1 kΩ at 25°C for the KTY83-110) to maximize the output voltage swing and measurement resolution.
For precision applications, the microcontroller's software uses a polynomial equation or a lookup table provided in the manufacturer's datasheet to convert the measured voltage (and thus resistance) into an accurate temperature value. This circuit requires a stable voltage reference and a precision resistor for accurate results. For noisy environments, a simple RC low-pass filter at the ADC input is recommended.
In summary, the NXP KTY83-110 is an exceptionally linear and robust silicon temperature sensor. Its simple two-wire interface and predictable behavior make it an ideal choice for designers seeking a reliable and straightforward solution for temperature monitoring across a vast array of applications, from automotive control units to industrial processing systems.
Keywords: Temperature Sensor, Silicon Sensor, Positive Temperature Coefficient, Linearity, Application Circuit.
