Infineon Technologies KT100

Overview

KT100 from Infineon Technologies is a silicon-based positive temperature coefficient (PTC) temperature sensor in TO-92 package, designed for analog temperature sensing in air/gas/liquid media. It exhibits R₂₅ = 1940–2060 Ω at 25 °C, operates from −50 °C to +150 °C, and delivers linearized resistance output with ±3% or ±1% tolerance. Used in motor winding protection, HVAC ambient sensing, and power supply thermal monitoring.

For engineers reviewing the KT100 datasheet, KT100 pinout, KT100 application, or KT100 equivalent, this page provides verified package mapping, validated thermal time constants (τ_air = 40 s), confirmed absolute maximum ratings (V_opmax = 25 V, I_opmax = 5 mA), and real-world use cases in thermal regulation circuits requiring polarity-independent, stable PTC response.

Technical Context

The KT100 implements a planar n-conducting silicon crystal element whose resistance follows a second-order polynomial function RT = R₂₅ × [1 + α·ΔT + β·(ΔT)²], with α = 7.88×10⁻³ K⁻¹ and β = 1.937×10⁻⁵ K⁻². Its symmetrical construction ensures polarity independence and eliminates orientation-dependent measurement error.

Thermal response is characterized by τ_air = 40 s (63% ΔT) and τ_oil = 4 s, enabling reliable integration into slow-to-moderate transient thermal environments such as transformer windings or refrigerant lines. The device requires 1 mA operating current for specified R₂₅ accuracy and avoids self-heating distortion under standard bias conditions.

Key Specifications

Pinout & Package

KT100 is housed in a TO-92 through-hole package with axial leads and symmetrical terminal geometry - no anode/cathode distinction. Electrical contact exists between Pin 1 and Pin 2 per package outline drawing; the third lead serves as mechanical support only.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar PTC temperature sensing applications.

Compared with KT100, KTY 10-6 offers tighter R₂₅ binning for improved absolute accuracy without circuit redesign, while KT 110 trades slower air response for smaller size and compatibility with compact thermal masses - both retain full functional equivalence in analog sensing topologies.

Availability

KT100 is available at Aetrix Electronics and suitable for motor winding protection, HVAC ambient sensing, and power supply thermal monitoring requiring stable component supply across extended industrial lifecycles.

Supply support for KT100 includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Infineon Technologies is a German semiconductor manufacturer specializing in power management, sensor, and automotive ICs, with global manufacturing and quality certification to ISO/TS 16949 and IECQ QC 080000.

The KT- and KTY-series was developed specifically for high-reliability analog temperature measurement in harsh industrial environments, emphasizing long-term drift stability, wide operating range, and mechanical robustness in TO-92 and SOT-23 formats.

FAQ

Is KT100 polarity-sensitive?

No. KT100 uses symmetrical construction with electrically connected Pins 1 and 2, making it fully polarity-independent. This eliminates orientation errors during manual assembly or automated placement and allows flexible routing in voltage-divider or constant-current configurations without regard to terminal assignment.

What is the recommended operating current for KT100?

The datasheet specifies 1 mA as the standard operating current for R₂₅ characterization and thermal modeling. At this bias, self-heating remains below 0.1 °C, preserving measurement accuracy. Current must not exceed 5 mA continuously or 7 mA peak (≤10 ms) to avoid permanent resistance shift or die damage.

Can KT100 be used in oil or liquid immersion?

Yes. KT100 achieves τ_oil = 4 s and is rated for −50 °C to +150 °C storage and operation. Its TO-92 epoxy body provides adequate sealing for non-corrosive oils and coolants. For aggressive refrigerants or saltwater, additional conformal coating or hermetic packaging is recommended per application validation.

How is temperature calculated from KT100 resistance?

Temperature is derived using the second-order equation T_A = [−α + √(α² − 4β × (1 − k_TT = R_T/R₂₅, α = 7.88×10⁻³ K⁻¹, and β = 1.937×10⁻⁵ K⁻². This formula is valid from −30 °C to +130 °C and yields ±0.3 °C typical accuracy with ±1% R₂₅ parts and calibrated coefficients.