Infineon Technologies KTY236

Overview

KTY236 from Infineon Technologies is a silicon-based positive temperature coefficient (PTC) temperature sensor in SOT-23 package, designed for precision analog temperature sensing in automotive and industrial control loops. It exhibits R₂₅ = 1005 Ω (min) / 1025 Ω (max) at 25 °C, operates from −50 °C to +150 °C, and delivers linearized resistance output with ±1% or ±3% tolerance options - used in motor winding temperature monitoring and HVAC refrigerant line sensing.

For engineers reviewing the KTY236 datasheet, KTY236 pinout, KTY236 application, or KTY236 equivalent, this device serves as a direct-resistance-output analog sensor requiring simple voltage-divider biasing, no external calibration, and compatibility with standard ADC front-ends in embedded thermal management systems.

Technical Context

The KTY236 implements a planar n-conducting silicon crystal element whose resistance follows a second-order polynomial function RT = R₂₅ × [1 + α·ΔT + β·(ΔT)²], where α = 7.88×10⁻³ K⁻¹ and β = 1.937×10⁻⁵ K⁻². Its symmetrical two-terminal construction eliminates polarity dependence and enables bidirectional current flow.

Thermal response is characterized by τ_air = 7 s and τ_oil = 1 s, supporting rapid detection of localized temperature shifts in liquid-cooled power electronics and engine coolant circuits without signal conditioning ICs.

Key Specifications

Pinout & Package

Two-terminal symmetrical device in SOT-23 package; no polarity assignment required. Electrical contact between Pin 1 and Pin 2 per package outline drawing - both terminals serve identical resistive sensing function.

Key Features

Applications

Equivalent & Alternatives

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

Compared with KTY237, KTY236 offers tighter R₂₅ tolerance matching in legacy designs; versus NTC alternatives, it eliminates software recalibration but requires lower-impedance signal chains to minimize noise sensitivity.

Availability

KTY236 is available at Aetrix Electronics and suitable for motor protection, HVAC refrigerant monitoring, automotive coolant sensing, and power supply thermal foldback requiring stable component supply across extended product lifecycles.

Supply support for KTY236 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.

KTY236 belongs to the KTY-series silicon PTC temperature sensors, engineered specifically for high-stability, low-drift analog temperature measurement in harsh environments where long-term calibration retention is critical.

FAQ

What is the maximum allowable bias current for KTY236 without self-heating error?

KTY236 must be operated at ≤7 mA continuous current to limit self-heating to <0.5 °C error. At 1 mA nominal bias, self-heating is negligible (<0.05 °C), making it ideal for precision applications. Peak current up to 10 mA is permitted for ≤10 ms pulses during transient measurements.

Can KTY236 be used in a Wheatstone bridge configuration?

Yes - KTY236's symmetrical two-terminal construction and tight R₂₅ tolerance (±1% option) allow direct integration into one arm of a Wheatstone bridge. Paired with a matched fixed resistor, it delivers differential output sensitive to ΔT with common-mode noise rejection, especially effective in electrically noisy motor drive environments.

Does KTY236 require external linearization circuitry?

No - KTY236 outputs a resistance that follows a known second-order polynomial (α = 7.88×10⁻³ K⁻¹, β = 1.937×10⁻⁵ K⁻²). Linearization is performed digitally in firmware using the equation T = [−α + √(α² − 4β(1 − kT))]/(2β), eliminating need for op-amp networks or analog ICs.

Is KTY236 RoHS compliant and halogen-free?

Yes - KTY236 meets RoHS Directive 2011/65/EU and is certified halogen-free per IEC 61249-2-21. The SOT-23 package uses lead-free matte tin plating, and the silicon die is fabricated in Infineon's fully qualified green manufacturing process with full material declaration available upon request.