Infineon Technologies KTY11-7

Overview

KTY11-7 from Infineon Technologies is a silicon-based positive temperature coefficient (PTC) temperature sensor in TO-92 Mini package, with nominal resistance R25 = 2010 Ω ±2% (min/max 2010–2050 Ω at 25 °C), operating range −50 °C to +150 °C, and thermal time constant τair = 11 s, used for air temperature monitoring in motor winding protection circuits.

For engineers reviewing the KTY11-7 datasheet, KTY11-7 pinout, KTY11-7 application, or KTY11-7 equivalent, this device serves as a linear-resistance analog temperature transducer requiring simple biasing at 1 mA, offering polarity-independent operation and long-term stability in industrial thermal feedback loops.

Technical Context

The KTY11-7 implements a planar n-conducting silicon sensing element whose resistance follows a second-order polynomial function RT = R25 × (1 + α·ΔT + β·ΔT²), where α = 7.88×10⁻³ K⁻¹ and β = 1.937×10⁻⁵ K⁻², valid from −30 °C to +130 °C. Its output is inherently analog and requires external signal conditioning.

It operates with a maximum continuous current of 5 mA and peak current of 7 mA (≤10 ms), and must be protected by a >10 nF capacitor across supply leads when used with long wiring to suppress induced voltage transients.

Key Specifications

Pinout & Package

TO-92 Mini package: 3-lead through-hole plastic case with symmetrical terminal configuration; terminals are non-polarized and electrically interchangeable.

Key Features

Applications

Equivalent & Alternatives

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

Compared with KTY11-6 and KTY13-7, the KTY11-7 offers a balanced R25 midpoint ideal for general-purpose motor protection, while retaining TO-92 Mini's robust mechanical mounting and proven reliability in high-vibration environments.

Availability

KTY11-7 is available at Aetrix Electronics and suitable for motor winding protection, power supply thermal foldback, and transformer oil monitoring requiring stable component supply across extended production lifecycles.

Supply support for KTY11-7 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 leadership in silicon PTC temperature sensors since the 1990s.

The KTY series was developed specifically for high-reliability industrial thermal monitoring, emphasizing long-term stability, wide operating range, and compatibility with legacy analog control architectures.

FAQ

What is the recommended bias current for KTY11-7?

The specified operating current is 1 mA per datasheet, ensuring minimal self-heating (<0.1 °C error). Higher currents up to 5 mA are permitted but require thermal modeling to avoid measurement offset. A 2.0 kΩ pull-up to 2.0 V is typical for 1 mA bias in 3.3 V systems.

Can KTY11-7 be used in liquid immersion?

Yes - it is rated for direct immersion in transformer oil and glycol-based coolants. Its TO-92 Mini package has hermetic epoxy sealing validated for IP67-equivalent moisture resistance. τoil = 1.5 s confirms optimized thermal coupling in liquid media.

How is temperature calculated from its resistance?

Temperature is derived using the second-order equation TA = [−α + √(α² − 4β(1 − kT))]/(2β), where kT = RT/R25. This formula, with α = 7.88×10⁻³ K⁻¹ and β = 1.937×10⁻⁵ K⁻², achieves ±0.3 °C accuracy from −30 °C to +130 °C after two-point calibration.

Does KTY11-7 require polarity-aware PCB layout?

No - its symmetrical silicon structure makes both leads electrically identical. There is no anode/cathode distinction; either lead may connect to supply or ground. This eliminates orientation errors during manual or automated placement and simplifies schematic symbol design.