KTY84-130 150 series

Core Principle: Silicon’s Resistive Temperature Dependence

KTY sensors are made from doped silicon (typically P-type or N-type). Their resistance changes with temperature due to two key factors:

Carrier Mobility (μ) Reduction with Temperature

At low temperatures, silicon’s crystal lattice vibrations are weak, allowing electrons/holes to move freely (low resistance).

As temperature rises, lattice vibrations increase, scattering charge carriers and reducing mobility (resistance increases).

Minority Carrier Activation (at High Temperatures)

Above ~150°C, intrinsic carriers (electron-hole pairs) become significant, slightly counteracting the PTC effect.

KTY sensors are designed to operate primarily in the PTC-dominant linear range (-50°C to +150°C).

Resistance vs. Temperature (Linear Approximation)

The resistance R(T)R(T) follows an almost linear relationship:

R(T)=R25⋅[1+α(T−25)]R(T)=R25​⋅[1+α(T−25)]

R25R25​: Resistance at 25°C (e.g., 1kΩ, 2kΩ).

αα: Temperature coefficient (~+0.8%/°C or 0.008/°C).

Example: A 2kΩ KTY sensor at 50°C:

R(50)=2kΩ⋅[1+0.008⋅(50−25)]=2.4kΩR(50)=2kΩ⋅[1+0.008⋅(50−25)]=2.4kΩ