Temperature Sensors - PTC Thermistors

Image Part Number Description / PDF Quantity Rfq
TFPT0805L3300KM

TFPT0805L3300KM

Vishay / Dale

THERMISTOR PTC 330 OHM 10% 0805

0

PTFT0805L0680JW

PTFT0805L0680JW

Vishay / Dale

THERMISTOR PTC 68 OHM 5% 0805

0

TFPT0805L1501FY

TFPT0805L1501FY

Vishay / Dale

THERMISTOR PTC 1.5K OHM 1% 0805

0

PTFT0603L6801JW

PTFT0603L6801JW

Vishay / Dale

THERMISTOR PTC 6.8K OHM 5% 0603

0

TFPT1206L1801FZ

TFPT1206L1801FZ

Vishay / Dale

THERMISTOR PTC 1.8K OHM 1% 1206

0

TFPT0603L3900KY

TFPT0603L3900KY

Vishay / Dale

THERMISTOR PTC 390 OHM 10% 0603

0

TFPT0805L4700JZ

TFPT0805L4700JZ

Vishay / Dale

THERMISTOR PTC 470 OHM 5% 0805

0

PTFT1206L0030JW

PTFT1206L0030JW

Vishay / Dale

THERMISTOR PTC 3 OHM 5% 1206

0

PTFT1206L0100JV

PTFT1206L0100JV

Vishay / Dale

THERMISTOR PTC 10 OHM 5% 1206

0

TFPT1206L2200FZ

TFPT1206L2200FZ

Vishay / Dale

THERMISTOR PTC 220 OHM 1% 1206

0

TFPT0603L3900JZ

TFPT0603L3900JZ

Vishay / Dale

THERMISTOR PTC 390 OHM 5% 0603

0

PTFT0805L0100JW

PTFT0805L0100JW

Vishay / Dale

THERMISTOR PTC 10 OHM 5% 0805

0

PTFT0805L2200JW

PTFT0805L2200JW

Vishay / Dale

THERMISTOR PTC 220 OHM 5% 0805

0

PTFT0805L6800JW

PTFT0805L6800JW

Vishay / Dale

THERMISTOR PTC 680 OHM 5% 0805

0

PTFT0805L1001JV

PTFT0805L1001JV

Vishay / Dale

THERMISTOR PTC 1K OHM 5% 0805

0

PTFT0805L0680JV

PTFT0805L0680JV

Vishay / Dale

THERMISTOR PTC 68 OHM 5% 0805

0

PTFT0603L1001JW

PTFT0603L1001JW

Vishay / Dale

THERMISTOR PTC 1K OHM 5% 0603

0

TFPT0805L1000JY

TFPT0805L1000JY

Vishay / Dale

THERMISTOR PTC 100 OHM 5% 0805

0

PTFT0805L1500JW

PTFT0805L1500JW

Vishay / Dale

THERMISTOR PTC 150 OHM 5% 0805

0

TFPT0805L3301JZ

TFPT0805L3301JZ

Vishay / Dale

THERMISTOR PTC 3.3K OHM 5% 0805

0

Temperature Sensors - PTC Thermistors

1. Overview

Positive Temperature Coefficient (PTC) thermistors are resistors with a positive temperature coefficient, meaning their resistance increases significantly with temperature rise. Unlike NTC thermistors, PTC devices exhibit a sharp resistance transition at a critical temperature (Curie point). They are widely used in overtemperature protection, self-regulating heating elements, and temperature sensing applications. Their inherent safety features and reliability make them critical components in modern electronics, automotive systems, and industrial equipment.

2. Main Types and Functional Classification

TypeFunctional CharacteristicsApplication Examples
Ceramic PTC ThermistorsHigh Curie temperature, abrupt resistance change, durableOverheat protection in motors, heaters, and power supplies
Polymer PTC ThermistorsLower switching temperature, resettable fuse functionalityUSB port protection, battery management systems
Switching PTCDigital on/off behavior at threshold temperatureThermal cutoff for appliances, HVAC systems
Linear PTCProportional resistance-temperature responsePrecision temperature measurement in industrial controllers

3. Structure and Composition

PTC thermistors typically consist of polycrystalline ceramic semiconductor materials (e.g., BaTiO3 doped with rare earth elements) with embedded silver or platinum electrodes. The core structure includes: - Semiconductor ceramic body with tailored Curie temperature - Metal electrodes for electrical connection - Protective epoxy or glass coating - Lead wires (axial/radial) or SMD terminations The PTC effect arises from the material's phase transition at Curie temperature, causing resistance spikes due to crystal lattice changes.

4. Key Technical Specifications

ParameterDescriptionImportance
R25 (Resistance at 25 C)Baseline resistance valueDetermines circuit compatibility
Tswitch (Switching Temperature)Critical temperature for resistance jumpApplication-specific threshold setting
Rmin/Rmax RatioResistance range spanIndicates sensitivity and switching capability
Dissipation Factor (mW/ C)Power dissipation per temperature unitAffects thermal response speed
Response Time (ms)Time to reach 90% resistance changeCritical for real-time protection systems

5. Application Fields

Major application sectors include: - Consumer Electronics: Smartphones (battery protection), 3D printers (hotend monitoring) - Automotive: EV battery thermal management, seat heater control - Industrial: Motor overload protection, pipeline freeze detection - Renewable Energy: Solar charge controllers, wind turbine gear monitoring - Medical: Patient warming systems, diagnostic equipment thermal regulation

6. Leading Manufacturers and Products

ManufacturerKey ProductsFeatures
Vishay BeyschlagK2500-FinderAutomotive-grade PTC with 50-150 C range
TE ConnectivityPS224-202UL-certified resettable fuse for power supplies
Murata ElectronicsPXU11S150R0Miniature SMD PTC for IoT devices
EPCOS (TDK)B59904C0150A070High-current PTC for industrial motor protection

7. Selection Guidelines

Key selection criteria: - Required switching temperature vs operating temperature range - Resistance tolerance and stability over lifespan - Package type (through-hole, SMD, bolt-on) - Voltage/current ratings with safety margin - Compliance with standards (UL, RoHS, AEC-Q200 for automotive) - Environmental resistance (humidity, vibration, chemical exposure)

8. Industry Trends

Emerging trends include: - Development of nano-ceramic materials for faster response times (<10ms) - Integration with MEMS technology for IoT sensor nodes - Higher temperature stability beyond 200 C for e-mobility applications - Miniaturization to 0402 SMD package sizes - AI-based predictive thermal management systems using PTC arrays - Increased adoption in hydrogen fuel cell thermal monitoring systems

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