Infineon Technologies KTY23-7

Overview

KTY23-7 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 (max), R₂₅ = 975 Ω (min), operates from −50 °C to +150 °C, and delivers linearized resistance output with ±1% or ±3% tolerance options - used in engine coolant monitoring and motor winding thermal protection.

For engineers reviewing the KTY23-7 datasheet, KTY23-7 pinout, KTY23-7 application, or KTY23-7 equivalent, this part serves as a low-cost, polarity-independent, two-terminal analog temperature transducer requiring only 1 mA bias current and offering fast thermal response (τ_air = 7 s, τ_oil = 1 s) in compact SMT form factor.

Technical Context

The KTY23-7 implements an n-conducting silicon planar junction whose resistance varies predictably with temperature according to a second-order polynomial: R_T = 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 concerns in circuit layout.

It functions as a passive, current-biased resistive element - not a voltage-output IC - requiring external signal conditioning. The device's thermal time constant in oil is 1 s, enabling rapid detection of localized temperature changes in liquid-cooled systems.

Key Specifications

Pinout & Package

Two-terminal device in SOT-23 package (JEDEC TO-236AB); symmetrical construction means Pin 1 and Pin 2 are electrically interchangeable - no polarity sensitivity. Package outline confirms mechanical compatibility with standard SOT-23 pick-and-place tooling and reflow profiles.

Key Features

Applications

Equivalent & Alternatives

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

Compared with KTY23-6 and NTCG163JH102HT1, the KTY23-7 offers superior high-temperature capability (+150 °C), inherent linearity over its full range, and immunity to polarity errors - making it optimal for automotive under-hood and industrial motor protection where reliability and simplicity are critical.

Availability

KTY23-7 is available at Aetrix Electronics and suitable for engine management systems, motor thermal protection circuits, inverter heatsink monitoring, and industrial pump safety cutoffs requiring stable component supply across extended temperature ranges and long product lifecycles.

Supply support for KTY23-7 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 AEC-Q200 for passive components.

The KTY-series is part of Infineon's analog temperature sensor portfolio, engineered specifically for robust, low-cost, high-reliability thermal monitoring in harsh environments - especially where long-term drift and thermal shock resistance are critical.

FAQ

What is the recommended bias current for KTY23-7?

The nominal operating current is 1 mA, per datasheet characterization. At this level, self-heating remains below 0.1 °C, preserving measurement accuracy. Peak current must not exceed 7 mA for ≤10 ms to avoid permanent damage. Higher currents induce measurable self-heating and accelerate long-term drift.

Can KTY23-7 be used in a Wheatstone bridge configuration?

Yes - its two-terminal, polarity-insensitive structure makes it ideal for one-arm bridge use with precision matched resistors. Bridge excitation voltage must be limited to maintain 1 mA through the sensor; typical implementation uses 1–2 V excitation with series limiting resistor or constant-current source.

Does KTY23-7 require calibration for accurate temperature readings?

Factory calibration is not required for most applications, as its resistance vs. temperature follows a well-defined second-order equation. For ±0.3 °C accuracy, software compensation using α and β coefficients suffices; high-precision systems may perform single-point (25 °C) or two-point (0 °C / 100 °C) calibration to correct unit-to-unit R₂₅ variation.

Is KTY23-7 AEC-Q200 qualified?

Yes - the KTY23-x family is explicitly qualified to AEC-Q200 Rev D for passive components. This includes testing for temperature cycling, humidity bias, mechanical shock, and long-term stability under automotive-grade stress conditions, confirming suitability for under-hood and powertrain applications.