NXP Semiconductors KTY81/220,116

Overview

KTY81/220,116 from NXP Semiconductors is a silicon-based positive temperature coefficient (PTC) temperature sensor in SOD70 plastic package, designed for precision measurement and control systems. It exhibits 1960–2040 Ω resistance at 25 °C, 0.79 %/K temperature coefficient, ±2.54 K max error at 25 °C, and operates from −55 °C to +150 °C - used in motor winding temperature monitoring, HVAC ambient sensing, and industrial thermostat feedback loops.

For engineers reviewing the KTY81/220,116 datasheet, KTY81/220,116 pinout, KTY81/220,116 application, or KTY81/220,116 equivalent, this page delivers verified specifications, thermal time constants in air/liquid, resistance vs. temperature tables, SOD70 mechanical dimensions, and direct alternatives with documented R25 and TC differences.

Technical Context

The KTY81/220,116 functions as a two-terminal linear-resistive temperature transducer with intrinsic PTC behavior. Its resistance varies predictably across −55 °C to +150 °C, enabling analog voltage-divider-based temperature readout without signal conditioning ICs.

It requires 1 mA continuous excitation current for optimal accuracy above 100 °C and exhibits thermal time constants of 30 s in still air, 5 s in still liquid, and 3 s in flowing liquid - critical for dynamic thermal response validation in closed-loop control designs.

Key Specifications

Pinout & Package

The KTY81/220,116 is housed in a SOD70 plastic near-cylindrical single-ended package with two in-line leads. Dimensions: 4.4–4.8 mm width, 5.0–5.2 mm height, 3.6–4.2 mm thickness, 2.54 mm lead pitch (bulk) or 5.08 mm (reel).

Key Features

Applications

Equivalent & Alternatives

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

Compared with KTY81/210 and KTY81/221, the KTY81/220,116 offers the widest R25 span (1960–2040 Ω) among /2xx variants, delivering optimal trade-off between calibration flexibility and high-temperature linearity up to 150 °C.

Availability

KTY81/220,116 is available at Aetrix Electronics and suitable for motor protection, HVAC control, industrial thermostat, and power supply thermal monitoring requiring stable component supply across automotive, industrial, and building automation programs.

Supply support for KTY81/220,116 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

NXP Semiconductors is a global semiconductor company headquartered in Eindhoven, Netherlands, specializing in secure connectivity solutions for automotive, industrial, and IoT applications.

The KTY81 series was developed by NXP as a family of silicon PTC temperature sensors targeting cost-sensitive, high-reliability analog thermal monitoring in harsh environments - emphasizing long-term stability, fail-safe behavior, and compatibility with standard PCB assembly processes.

FAQ

What is the recommended operating current for KTY81/220,116 to minimize self-heating error?

The KTY81/220,116 should be operated at 1 mA continuous current for temperatures above 100 °C to keep self-heating-induced temperature error below ±0.5 K. At lower temperatures, currents up to 2 mA are permissible per limiting values, but 1 mA remains optimal for consistent calibration across the full −55 °C to +150 °C range. This value is explicitly specified in Table 6 and Figure 1b of the NXP datasheet.

Does KTY81/220,116 require polarity-aware PCB layout?

No, the KTY81/220,116 has no polarity - both terminals (Pin 1 and Pin 2) are electrically identical electrical contacts. The device functions as an unpolarized two-terminal resistor, and orientation on the PCB does not affect performance. This is confirmed in Table 2 ("Pinning") and Figure 4 (SOD70 outline), which show symmetric lead placement and no marking differentiation.

How does the thermal time constant of KTY81/220,116 impact its use in fast-response temperature control loops?

The KTY81/220,116 has a thermal time constant of 30 s in still air, 5 s in still liquid, and 3 s in flowing liquid. In closed-loop control, this means the sensor reaches 63.2% of a step temperature change within those intervals - making it suitable for HVAC and motor protection where response times >5 s are acceptable, but unsuitable for sub-second thermal event detection. These values are measured per IEC 60134 and published in Table 6.

Can KTY81/220,116 be used in automotive under-hood applications?

Yes, the KTY81/220,116 is rated for −55 °C to +150 °C ambient operation and qualified per IEC 60134 limiting values - meeting under-hood requirements for engine coolant, transmission oil, and power electronics thermal monitoring. Its SOD70 package provides mechanical robustness, and long-term drift ≤3.2 Ω after 10,000 h at 150 °C supports 15-year automotive service life. These specs are validated in Tables 5 and 6.

What is the maximum expected temperature error of KTY81/220,116 at 100 °C?

At 100 °C, the KTY81/220,116 exhibits a maximum expected temperature error of ±5.05 K, as documented in Table 10 for the /220 variant. This error arises from resistance tolerance and TC nonlinearity, and is measured with 1 mA excitation current in liquid medium. For improved accuracy, system-level two-point calibration at 25 °C and 100 °C is recommended.