Temperature Sensors - NTC Thermistors

Image	Part Number	Description / PDF	Quantity	Rfq
	SM103F5K Wickmann / Littelfuse	THERMISTOR NTC 10KOHM 3419K MELF	0
	USUR1000-102G-03 Wickmann / Littelfuse	THERM NTC 1KOHM 3892K RING LUG	0
	SM105V3K Wickmann / Littelfuse	THERMISTOR NTC 1MOHM 4369K MELF	0
	USUR1000-103K Wickmann / Littelfuse	THERM NTC 10KOHM 3892K RING LUG	0
	USX2569 Wickmann / Littelfuse	THERMISTOR NTC 10KOHM 3892K DO35	0
	303HG1K Wickmann / Littelfuse	THERMISTOR NTC 30KOHM 3810K DO35	0
	USUR1000-303K Wickmann / Littelfuse	THERM NTC 30KOHM 3892K RING LUG	0
	USUR1000-203K Wickmann / Littelfuse	THERM NTC 20KOHM 3892K RING LUG	0
	LR253K0F Wickmann / Littelfuse	THERMISTOR 25KOHM 1206 1%	0
	USX2210 Wickmann / Littelfuse	THERMISTOR NTC 10KOHM 3892K BEAD	0
	103GG1K Wickmann / Littelfuse	THERMISTOR NTC 10KOHM 3575K DO35	0
	SP102F1J Wickmann / Littelfuse	THERMISTOR NTC 1KOHM 3419K PROBE	0
	USP9728 Wickmann / Littelfuse	THERM NTC 100KOHM 3892K PROBE	0
	102BG1K Wickmann / Littelfuse	THERMISTOR NTC 1KOHM 2941K DO35	0
	254JG1K Wickmann / Littelfuse	THERM NTC 250KOHM 3892K DO35	0
	PR502J2 Wickmann / Littelfuse	THERMISTOR NTC 5KOHM 3892K BEAD	0
	USUR1000-302G-36 Wickmann / Littelfuse	THERM NTC 3KOHM 3892K RING LUG	0
	BC222J1K Wickmann / Littelfuse	THERM NTC 2.252KOHM 3892K CHIP	0
	USP5510 Wickmann / Littelfuse	THERMISTOR NTC 10KOHM 3892K FLAG	0
	BC101B1K Wickmann / Littelfuse	THERMISTOR NTC 100OHM 2941K CHIP	0

Temperature Sensors - NTC Thermistors

1. Overview

NTC (Negative Temperature Coefficient) thermistors are temperature-sensitive resistors whose resistance decreases with increasing temperature. This semiconductor ceramic device utilizes metal oxide materials to achieve precise temperature measurement and control. As a fundamental component in thermal management systems, NTC thermistors play critical roles in modern electronics, automotive engineering, and industrial automation due to their high sensitivity ( : 2000-5000 K) and accuracy ( 0.1 C to 5 C).

2. Major Types and Functional Classification

Type	Functional Characteristics	Application Examples
Bead Thermistors	Small size ( 0.5-5mm), fast response (<50ms), glass-encapsulated	Medical probes, liquid temperature monitoring
Disk Thermistors	Higher power rating, epoxy-coated, axial leads	Power supply thermal protection, HVAC systems
Chip Thermistors	SMD packaging, low profile (0.6-3.2mm), RoHS compliant	Smartphone thermal management, wearable devices
Glass-Encapsulated	Hermetic seal, corrosion resistance, operating temp: -50 C to +300 C	Automotive battery monitoring, aerospace sensors

3. Structure and Composition

Typical NTC thermistor construction includes:

Semiconductive ceramic core (Mn-Ni-Co-Ox system)
Platinum alloy electrode layers (sintered or plated)
Protective epoxy/glass encapsulation (IP67 rated)
Lead wires (Cu/Ni alloy, 26-34 AWG)

Manufacturing process involves powder synthesis at 1500 C, isostatic pressing, and controlled atmosphere sintering to achieve desired R-T characteristics.

4. Key Technical Specifications

Parameter	Description	Significance
Rated Resistance (R25)	Resistance at 25 C (100 -10M range)	System compatibility, signal conditioning design
B-Value (K)	Material constant (2000-5000K)	Determines sensitivity across operating range
Tolerance	Resistance deviation ( 1% to 15%)	Affects measurement accuracy
Operating Temp Range	-100 C to +600 C (varies by type)	Environmental suitability
Dissipation Factor	mW/ C (self-heating coefficient)	Power consumption and stability considerations

5. Application Fields

Primary industries utilizing NTC thermistors:

Industrial: Process control ( 0.5 C accuracy), motor protection
Consumer Electronics: Battery management (Li-ion charging), smart thermostats
Medical: Patient monitoring (Class F accuracy), lab equipment
Automotive: Battery pack thermal monitoring (ISO 14001 compliance), ECU protection

Notable application example: Tesla Model S battery management system uses 48-channel NTC array for cell temperature monitoring ( 1 C accuracy).

6. Leading Manufacturers and Products

Manufacturer	Key Products	Technical Highlights
Murata Electronics	NXFT Series	Automotive-grade (AEC-Q200), 0.5 C accuracy, -50 C to +150 C range
TE Connectivity	NTCLE Series	Medical certification (IEC 60601), 3.2mm chip format
Vishay Beyschlag	NTCAl Series	Aluminum housing, 50W power handling, IP68 rating

7. Selection Guidelines

Key considerations for NTC thermistor selection:

Resistance-Temperature curve matching application requirements
Environmental factors: humidity (IP rating), vibration (automotive shock specs)
Electrical parameters: operating current (self-heating effects)
Form factor constraints (SMD vs through-hole)
Calibration requirements (standard vs customized R-T tables)

Recommend verifying long-term stability (aging rate <0.2%/year) and RoHS compliance for production applications.

8. Industry Trends

Emerging developments include:

Micro-NTC fabrication (MEMS-based, <0.1mm chips)
High-temperature stability improvements (up to 600 C operation)
Integration with wireless sensor networks (Zigbee/LoRa compatibility)
AI-enhanced linearization algorithms (reducing external circuit complexity)

Market growth projected at 8.2% CAGR through 2027 driven by EV battery management demands.