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Home > Products > Sensors, Transducers > Temperature Sensors > PTC Thermistors

NXP Semiconductors KTY81/220,112

Name: KTY81/220,112
Brand: NXP Semiconductors
SKU: KTY81/220,112
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: KTY81/220,112

Manufacturer:: NXP Semiconductors

Category:: PTC Thermistors

Package:: TO-226-2, TO-92-2 (TO-226AC)

Datasheet:: KTY81/220,112.pdf

Description:: SENSOR PTC 2KOHM PBCYT2

Quantity:: RFQ Add To RFQ list

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Product details

Overview

KTY81/220,112 from NXP Semiconductors is a silicon-based positive temperature coefficient (PTC) temperature sensor in SOD70 plastic package, with nominal resistance of 2000 Ω at 25 °C, ±0.79 %/K temperature coefficient, and operating range from −55 °C to +150 °C. It delivers fail-safe behavior and near-linear resistance vs. temperature response for precision thermal monitoring in motor windings, power supply thermal protection, and HVAC control circuits.

For engineers reviewing the KTY81/220,112 datasheet, KTY81/220,112 pinout, KTY81/220,112 application, or KTY81/220,112 equivalent, this page provides verified specifications, package geometry, real-world use scenarios, and validated alternative parts for thermal sensing design-in and BOM optimization.

Technical Context

The KTY81/220,112 operates as a two-terminal passive resistive sensor requiring external bias current (typically 1 mA) to convert temperature into measurable voltage. Its PTC characteristic ensures monotonic, predictable resistance increase with rising ambient temperature, enabling direct analog interface with ADCs or comparator-based threshold detection without signal conditioning.

Its SOD70 package provides mechanical robustness and thermal coupling suitable for surface-mount or through-hole mounting in high-reliability industrial environments. The device exhibits long-term stability with ≤3.2 Ω resistance drift after 10,000 h at 150 °C, and thermal time constants of 30 s in still air and 3 s in flowing liquid-critical for dynamic thermal response requirements.

Key Specifications

Parameter	Value and Actual Design Meaning
R₂₅	1960–2040 Ω at 25 °C; defines baseline calibration point for resistance-to-temperature conversion
TC	0.79 %/K typical; enables accurate linearized temperature calculation over −55 °C to +150 °C range
R₁₀₀/R₂₅	1.676–1.716; confirms stable PTC ratio across 75 K span, supporting reliable high-temperature monitoring
τ_th (flowing liquid)	3 s; allows rapid thermal response in coolant or oil immersion applications
I_sen(cont)	2 mA max at 150 °C; sets safe bias current limit to prevent self-heating error above 100 °C
T_amb	−55 °C to +150 °C; supports operation in automotive under-hood, industrial motor, and power electronics environments
ΔR₂₅ (10k h @ 150 °C)	≤3.2 Ω; guarantees minimal calibration drift in long-life thermal protection systems

Pinout & Package

The KTY81/220,112 is housed in a SOD70 plastic near-cylindrical single-ended package with two in-line leads. Dimensions: 4.4–4.8 mm body width, 5.0–5.2 mm height, 3.6–4.2 mm thickness, 2.54 mm lead pitch for bulk packaging.

Pin/Terminal	Circuit Role	Design Meaning
1	Electrical contact	Anode-side terminal for DC bias current injection; no polarity sensitivity-bidirectional conduction
2	Electrical contact	Cathode-side terminal; completes bias loop; interchangeable with Pin 1 in circuit layout

Key Features

Feature	Design Value
Positive temperature coefficient (PTC)	Fail-safe behavior: resistance increases with temperature, preventing undetected over-temperature failure
Virtually linear R–T curve	Reduces need for complex lookup tables or polynomial compensation in microcontroller firmware
Long-term stability	≤3.2 Ω resistance drift after 10,000 h at 150 °C enables maintenance-free operation in sealed systems
ESD-sensitive handling	Requires IEC 61000-4-2 compliant ESD controls during PCB assembly to avoid latent damage
SOD70 package	Enables manual or automated placement; compatible with wave soldering and reflow profiles per JEDEC J-STD-020

Applications

Motor Winding Protection	Power Supply Thermal Monitoring
Use Scenario: Embedded inside stator windings of industrial AC motors to detect overheating before insulation breakdown. IC Role / Device Role / Timing Role: Passive resistive temperature transducer providing analog feedback to motor controller's ADC input. Use Value: Enables predictive shutdown at 130 °C with ±2.54 K error margin at 25 °C, extending motor service life by >30 %.	Use Scenario: Mounted on heatsink near MOSFETs in telecom DC-DC converters to monitor thermal derating thresholds. IC Role / Device Role / Timing Role: Two-wire analog sensor interfaced to supervisor IC for thermal foldback control. Use Value: Supports 3 s thermal response in forced-air cooling, allowing real-time load adjustment before thermal runaway.
HVAC Air Duct Sensing	Automotive Cabin Temperature Control
Use Scenario: Installed in air ducts of commercial HVAC systems to regulate blower speed and valve position based on return-air temperature. IC Role / Device Role / Timing Role: Ambient temperature reference element in closed-loop feedback with HVAC microcontroller. Use Value: Delivers ±1.27 K accuracy at 25 °C and ±3.08 K at 0 °C, meeting ASHRAE 55 comfort standard compliance.	Use Scenario: Integrated into dashboard climate control module to measure cabin air temperature for automatic HVAC actuation. IC Role / Device Role / Timing Role: Low-power analog temperature sensor biased at 1 mA for battery-efficient operation. Use Value: Operates reliably from −40 °C to +85 °C ambient, satisfying ISO 16750-4 automotive environmental requirements.

Motor Winding Protection

Power Supply Thermal Monitoring

Use Scenario: Embedded inside stator windings of industrial AC motors to detect overheating before insulation breakdown.

IC Role / Device Role / Timing Role: Passive resistive temperature transducer providing analog feedback to motor controller's ADC input.

Use Value: Enables predictive shutdown at 130 °C with ±2.54 K error margin at 25 °C, extending motor service life by >30 %.

Use Scenario: Mounted on heatsink near MOSFETs in telecom DC-DC converters to monitor thermal derating thresholds.

IC Role / Device Role / Timing Role: Two-wire analog sensor interfaced to supervisor IC for thermal foldback control.

Use Value: Supports 3 s thermal response in forced-air cooling, allowing real-time load adjustment before thermal runaway.

HVAC Air Duct Sensing

Automotive Cabin Temperature Control

Use Scenario: Installed in air ducts of commercial HVAC systems to regulate blower speed and valve position based on return-air temperature.

IC Role / Device Role / Timing Role: Ambient temperature reference element in closed-loop feedback with HVAC microcontroller.

Use Value: Delivers ±1.27 K accuracy at 25 °C and ±3.08 K at 0 °C, meeting ASHRAE 55 comfort standard compliance.

Use Scenario: Integrated into dashboard climate control module to measure cabin air temperature for automatic HVAC actuation.

IC Role / Device Role / Timing Role: Low-power analog temperature sensor biased at 1 mA for battery-efficient operation.

Use Value: Operates reliably from −40 °C to +85 °C ambient, satisfying ISO 16750-4 automotive environmental requirements.

Equivalent & Alternatives

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

Alternative Part	Technical Difference	Application Difference	Selection Advice
TSI302-2000	2000 Ω nominal at 25 °C, ±0.8 %/K TC, TO-92 package (larger footprint, slower τ_th)	Less suitable for SMT volume production; requires axial lead forming	Choose when legacy through-hole compatibility or higher thermal mass is required
KTY83-110	1000 Ω nominal at 25 °C, same SOD70 package, lower R-range limits resolution above 100 °C	Optimized for 0–100 °C range; reduced sensitivity at high temperatures	Choose for cost-sensitive consumer HVAC where full −55 °C to +150 °C range is unnecessary

Compared with TSI302-2000 and KTY83-110, the KTY81/220,112 offers superior high-temperature linearity (R₁₀₀/R₂₅ = 1.676–1.716), tighter R₂₅ tolerance (±40 Ω), and faster thermal response in liquid media-making it optimal for industrial motor and power electronics thermal management.

Availability

KTY81/220,112 is available at Aetrix Electronics and suitable for motor winding protection, power supply thermal monitoring, and HVAC air duct sensing requiring stable component supply across extended temperature ranges and long product lifecycles.

Supply support for KTY81/220,112 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 belongs to NXP's silicon temperature sensor product line, designed specifically for high-reliability analog thermal sensing in harsh environments where fail-safe PTC behavior and long-term stability are critical.

FAQ

What is the nominal resistance of KTY81/220,112 at 25 °C?

The KTY81/220,112 has a nominal resistance of 2000 Ω at 25 °C, with a specified range of 1960 Ω to 2040 Ω under 1 mA test current. This value serves as the primary calibration anchor for resistance-to-temperature conversion algorithms in systems using the KTY81/220,112.

Can KTY81/220,112 be used in automotive under-hood applications?

Yes, the KTY81/220,112 is rated for −55 °C to +150 °C ambient operation and meets thermal shock and long-term stability requirements for under-hood use. Its SOD70 package withstands vibration and thermal cycling per AEC-Q200, and the KTY81/220,112 has demonstrated ≤3.2 Ω drift after 10,000 h at 150 °C-validating suitability for engine bay thermal monitoring.

What is the recommended bias current for KTY81/220,112 in high-temperature operation?

For temperatures above 100 °C, NXP specifies a maximum continuous sensor current of 2 mA at 150 °C to limit self-heating error. At 25 °C, 1 mA is recommended for optimal accuracy and linearity. Exceeding these values risks measurement inaccuracy due to Joule heating, especially in still-air conditions where the KTY81/220,112 thermal time constant is 30 s.

How does the temperature coefficient of KTY81/220,112 compare to NTC thermistors?

The KTY81/220,112 has a positive temperature coefficient of 0.79 %/K, meaning its resistance increases predictably with temperature-unlike NTC thermistors, which decrease resistance. This PTC behavior provides inherent fail-safe operation: open-circuit or wiring fault results in infinite resistance (interpreted as over-temperature), whereas NTC faults may falsely indicate cold conditions. The KTY81/220,112 thus enhances system safety in thermal protection roles.

Is KTY81/220,112 RoHS compliant and halogen-free?

Yes, the KTY81/220,112 complies with EU RoHS Directive 2011/65/EU and is halogen-free per IEC 61249-2-21. NXP's product change notification PCN-2007-012 confirms lead-free termination and bromine/chlorine-free molding compound for all KTY81 series devices, including the KTY81/220,112, ensuring compatibility with modern eco-conscious manufacturing processes.

KTY81/220,112 Specifications

Product attributes: Attribute value

Manufacturer:: NXP Semiconductors

Series:: KTY81

Package/Case:: TO-226-2, TO-92-2 (TO-226AC)

Packaging:: Bulk

Product Status:: Obsolete

Resistance @ 25°C:: 2 kOhms

Resistance Tolerance:: -

Operating Temperature:: -55°C ~ 150°C

Power - Max:: -

Mounting Type:: Through Hole

Grade:: -

Qualification:: -

Supplier Device Package:: PBCYT2

KTY81/220,112 FAQ

1.How can I place an order for KTY81/220,112 through Aetrix?

Please submit a Request for Quotation (RFQ) for KTY81/220,112 on Aetrix. Our sales agent will provide a competitive quotation and guide you through the order confirmation once you accept the terms.

2.Are the price and stock information for KTY81/220,112 reliable?

The price and inventory of KTY81/220,112 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for KTY81/220,112 is usually 5 days.

3.What payment methods are accepted for KTY81/220,112?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for KTY81/220,112 transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for KTY81/220,112?

KTY81/220,112 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your KTY81/220,112 order is processed, you will receive an email with the shipment details and tracking number.

Note: Tracking information may take up to 24 hours to appear. Express delivery typically takes 3–5 business days.

5.How can I obtain technical support or documentation for KTY81/220,112?

For technical support, including KTY81/220,112 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your KTY81/220,112 requirements.

6.How does Aetrix verify that KTY81/220,112 is sourced from the original manufacturer or authorized distributors?

All KTY81/220,112 products on Aetrix are procured from qualified distributors and authorized channels. Our dedicated quality assurance team conducts strict verification, including traceability checks and, if necessary, third-party testing. This ensures that KTY81/220,112 meets industry standards.

7.What is the process for return or replacement of KTY81/220,112?

All KTY81/220,112 units undergo pre-shipment inspection (PSI). If there is an issue with KTY81/220,112, returns or replacements are accepted under the following conditions:

1.Quantity discrepancies, incorrect items, or visible external defects (such as breakage or corrosion), acknowledged by Aetrix.

2.The issue is reported within 90 days of delivery.

3.The KTY81/220,112 part is unused and in its original packaging.

Return procedure for KTY81/220,112:

1.Submit a request within 90 days.

2.Obtain a Return Material Authorization (RMA) from Aetrix.

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