NTC0402 Series 0402-Size Chip NTC Thermistors
The NYFEA NTC0402 Series comprises passive, two-terminal, surface-mount negative-temperature-coefficient thermistors in the 0402 imperial (1005 metric) size. The product specification lists nominal zero-power resistance at 25 °C (R25) values from 10 kΩ to 470 kΩ, R25 tolerance grades of ±1%, ±3%, or ±5% in the listed combinations, and part-specific B-constant characteristics.
Product scope: NTC0402 is a resistive sensing element, not a digital temperature-sensor IC or a self-contained protection device. The external system must provide controlled excitation, analog measurement, resistance-to-temperature conversion, calibration where required, suitable thermal coupling, diagnostics, and the final protection response.
Use the applicable controlled specification for purchasing, incoming inspection, PCB release, soldering approval and production qualification.
NTC0402 Product Overview and Scope
NTC0402 is a negative-temperature-coefficient sensing element whose resistance decreases as temperature increases. The compact 0402 package supports temperature measurement where PCB area is constrained, but pad geometry, solder symmetry, board flex, excitation power, copper heat spreading and nearby heat sources can materially affect the result.
| Selection question | NTC0402 specification | System-level decision |
|---|---|---|
| What component category is it? | Passive, two-terminal chip NTC thermistor. | Provide excitation, ADC measurement, linearization and fault handling externally. |
| Which nominal R25 values are listed? | 10 kΩ, 22 kΩ, 33 kΩ, 47 kΩ, 68 kΩ, 100 kΩ and 470 kΩ at 25 °C. | Select for ADC range, resolution, leakage, excitation power and temperature span. |
| Which R25 tolerances are listed? | F: ±1%; H: ±3%; J: ±5%. The 470 kΩ configuration is listed only in F and J. | Use the exact orderable code; do not infer an unlisted tolerance combination. |
| What are the thermal ratings? | 1.0 mW/°C dissipation factor; <3 s thermal time constant; 100 mW rated power at 25 °C. | Do not treat rated power as recommended measurement power or the IC-level response as finished-system response. |
| What is the operating range? | −40 °C to +125 °C ambient. | Qualify the complete mounting, environment and mission profile. |
Ordering Codes and Part-Number Selection
Selection Highlights
- 0402 SMD format: 1.00 ±0.15 mm × 0.50 ±0.15 mm × 0.50 ±0.15 mm.
- Seven listed R25 values: 10 kΩ, 22 kΩ, 33 kΩ, 47 kΩ, 68 kΩ, 100 kΩ and 470 kΩ.
- R25 tolerance grades: ±1%, ±3% and ±5% in the listed combinations; the 470 kΩ version is listed only in ±1% and ±5%.
- Thermal characteristics: <3 s thermal time constant and 1.0 mW/°C dissipation factor under the product-specification methods.
- Operating range: −40 °C to +125 °C ambient.
- Packing: paper carrier tape, 10,000 units per reel.
How to Read the Listed Part Numbers
| Field | Meaning | Values relevant to the listed NTC0402 range |
|---|---|---|
| NTC | Component category | Chip NTC thermistor |
| 0402 | External size code | 1.00 × 0.50 × 0.50 mm |
| X | Delimiter | Fixed delimiter in the ordering format |
| 103 / 223 / 333 / 473 / 683 / 104 / 474 | Nominal resistance code at 25 °C | 10 kΩ / 22 kΩ / 33 kΩ / 47 kΩ / 68 kΩ / 100 kΩ / 470 kΩ |
| F / H / J | R25 tolerance | ±1% / ±3% / ±5%; 470 kΩ is listed only in F and J |
| 3435 / 3450 / 3950 / 4050 / 4150 / 4250 | B-constant code | Interpret with the final A or B calculation-interval code |
| F | B-constant tolerance code | ±1% for the B value explicitly identified with a tolerance |
| A / B | B calculation temperatures | A: 25 °C and 85 °C; B: 25 °C and 50 °C |
Part Numbers Listed in the Product Specification
The specification lists 29 complete orderable combinations. Values and tolerance placement below follow the electrical table; an omitted B-value tolerance is not inferred.
| Listed part number | Nominal R25 and tolerance | B25/50 | B25/85 | Permissible current at 25 °C |
|---|---|---|---|---|
| NTC0402X103F3435FA | 10 kΩ ±1% | 3380 K ±1% | 3435 K ±1% | 0.31 mA |
| NTC0402X103F3450FB | 10 kΩ ±1% | 3450 K ±1% | 3500 K | 0.31 mA |
| NTC0402X103F3950FB | 10 kΩ ±1% | 3950 K ±1% | 3987 K | 0.31 mA |
| NTC0402X223F3950FB | 22 kΩ ±1% | 3950 K ±1% | 3987 K | 0.21 mA |
| NTC0402X333F4050FB | 33 kΩ ±1% | 4050 K ±1% | 4100 K | 0.17 mA |
| NTC0402X473F4050FB | 47 kΩ ±1% | 4050 K ±1% | 4100 K | 0.14 mA |
| NTC0402X683F4150FB | 68 kΩ ±1% | 4150 K ±1% | 4210 K | 0.12 mA |
| NTC0402X104F3950FB | 100 kΩ ±1% | 3950 K ±1% | 3987 K | 0.10 mA |
| NTC0402X104F4250FB | 100 kΩ ±1% | 4250 K ±1% | 4310 K | 0.10 mA |
| NTC0402X474F4050FA | 470 kΩ ±1% | 4000 K ±1% | 4050 K ±1% | 0.04 mA |
| NTC0402X103H3435FA | 10 kΩ ±3% | 3380 K ±1% | 3435 K ±1% | 0.31 mA |
| NTC0402X103H3450FB | 10 kΩ ±3% | 3450 K ±1% | 3500 K | 0.31 mA |
| NTC0402X103H3950FB | 10 kΩ ±3% | 3950 K ±1% | 3987 K | 0.31 mA |
| NTC0402X223H3950FB | 22 kΩ ±3% | 3950 K ±1% | 3987 K | 0.21 mA |
| NTC0402X333H4050FB | 33 kΩ ±3% | 4050 K ±1% | 4100 K | 0.17 mA |
| NTC0402X473H4050FB | 47 kΩ ±3% | 4050 K ±1% | 4100 K | 0.14 mA |
| NTC0402X683H4150FB | 68 kΩ ±3% | 4150 K ±1% | 4210 K | 0.12 mA |
| NTC0402X104H3950FB | 100 kΩ ±3% | 3950 K ±1% | 3987 K | 0.10 mA |
| NTC0402X104H4250FB | 100 kΩ ±3% | 4250 K ±1% | 4310 K | 0.10 mA |
| NTC0402X103J3435FA | 10 kΩ ±5% | 3380 K ±1% | 3435 K ±1% | 0.31 mA |
| NTC0402X103J3450FB | 10 kΩ ±5% | 3450 K ±1% | 3500 K | 0.31 mA |
| NTC0402X103J3950FB | 10 kΩ ±5% | 3950 K ±1% | 3987 K | 0.31 mA |
| NTC0402X223J3950FB | 22 kΩ ±5% | 3950 K ±1% | 3987 K | 0.21 mA |
| NTC0402X333J4050FB | 33 kΩ ±5% | 4050 K ±1% | 4100 K | 0.17 mA |
| NTC0402X473J4050FB | 47 kΩ ±5% | 4050 K ±1% | 4100 K | 0.14 mA |
| NTC0402X683J4150FB | 68 kΩ ±5% | 4150 K ±1% | 4210 K | 0.12 mA |
| NTC0402X104J3950FB | 100 kΩ ±5% | 3950 K ±1% | 3987 K | 0.10 mA |
| NTC0402X104J4250FB | 100 kΩ ±5% | 4250 K ±1% | 4310 K | 0.10 mA |
| NTC0402X474J4050FA | 470 kΩ ±5% | 4000 K ±1% | 4050 K ±1% | 0.04 mA |
The bracket notation used later is only a family summary. Purchase and qualify a complete listed part number. In particular, NTC0402X474H4050FA is not listed.
NTC Principle, B-Constant Method, and R–T Approximation
NTC0402 has no digital interface. Its output is resistance, which the host circuit measures and converts to temperature using the exact part number's R25 and B data or a separately validated R–T lookup table.
Analog resistance
Two terminals; polarity independent for ordinary resistance measurement.
R25 at 25 °C
Nominal zero-power resistance is specified at 25 °C.
B constant
Use the calculation interval stated by the exact orderable code.
Host responsibility
ADC conversion, linearization, calibration, diagnostics and fault response are external.
For preliminary calculations, the B-parameter approximation is commonly written as R(T) = R25 × exp[B × (1/T − 1/T25)], with T and T25 in kelvin and T25 = 298.15 K. It is an engineering approximation over the interval associated with the stated B constant. Do not substitute B25/50 for B25/85 or treat one B value as a guaranteed full-range R–T curve.
Measurement Circuit, ADC Readout, and Fault Detection
The designer selects the excitation and readout topology to suit the resistance range, temperature span, ADC reference, measurement-uncertainty target, allowable self-heating, sample rate and required diagnostic coverage.
Excitation Power, Self-Heating, and Measurement Error
NTC0402 has no supply current or sleep mode. External excitation determines its power dissipation and the resulting self-heating error.
| Nominal R25 | Permissible operating current at 25 °C | Calculated I²R at nominal R25 | Specification definition |
|---|---|---|---|
| 10 kΩ | 0.31 mA | 0.96 mW | Current that produces a 1 °C body-temperature rise on the PCB in still air. |
| 22 kΩ | 0.21 mA | 0.97 mW | Current that produces a 1 °C body-temperature rise on the PCB in still air. |
| 33 kΩ | 0.17 mA | 0.95 mW | Current that produces a 1 °C body-temperature rise on the PCB in still air. |
| 47 kΩ | 0.14 mA | 0.92 mW | Current that produces a 1 °C body-temperature rise on the PCB in still air. |
| 68 kΩ | 0.12 mA | 0.98 mW | Current that produces a 1 °C body-temperature rise on the PCB in still air. |
| 100 kΩ | 0.10 mA | 1.00 mW | Current that produces a 1 °C body-temperature rise on the PCB in still air. |
| 470 kΩ | 0.04 mA | 0.75 mW | Current that produces a 1 °C body-temperature rise on the PCB in still air. |
I²R values are rounded calculations from nominal R25 and the listed permissible current; they are not additional guaranteed parameters. Where self-heating is material to the error budget, use lower continuous current or duty-cycled excitation and verify performance on the final PCB in the final enclosure.
Zero-Power Measurement Reference
The R25 method uses 25 ±0.05 °C and measurement power ≤0.1 mW. Calculate worst-case power across resistance, supply and component tolerances; do not confuse this test condition with a universal production-circuit setting.
Electrical Characteristics, Test Conditions, and Dimensions
Specification Test and Measurement Conditions
| Measurement or test | Condition stated in the product specification | Engineering interpretation |
|---|---|---|
| Standard atmospheric conditions | 20 ±15 °C; 65 ±20% RH; 86 kPa to 106 kPa | Applicable unless a different condition is specified. |
| Reference conditions if results are in doubt | 25 ±2 °C; 65 ±5% RH; 86 kPa to 106 kPa | Use these tighter limits to resolve disputed results. |
| Nominal zero-power resistance R25 | 25 ±0.05 °C; measuring power ≤0.1 mW | Characterization condition, not a production-circuit excitation recommendation. |
| Nominal B constant | Resistance at 25 ±0.05 °C and 50 ±0.05 °C or 85 ±0.05 °C | Use kelvin and the interval identified by the exact part number. |
Listed Electrical Configurations
| Nominal R25 | Listed part-number family | B25/50 | B25/85 | Permissible current at 25 °C |
|---|---|---|---|---|
| 10 kΩ | NTC0402X103[F/H/J]3435FA | 3380 K ±1% | 3435 K ±1% | 0.31 mA |
| 10 kΩ | NTC0402X103[F/H/J]3450FB | 3450 K ±1% | 3500 K | 0.31 mA |
| 10 kΩ | NTC0402X103[F/H/J]3950FB | 3950 K ±1% | 3987 K | 0.31 mA |
| 22 kΩ | NTC0402X223[F/H/J]3950FB | 3950 K ±1% | 3987 K | 0.21 mA |
| 33 kΩ | NTC0402X333[F/H/J]4050FB | 4050 K ±1% | 4100 K | 0.17 mA |
| 47 kΩ | NTC0402X473[F/H/J]4050FB | 4050 K ±1% | 4100 K | 0.14 mA |
| 68 kΩ | NTC0402X683[F/H/J]4150FB | 4150 K ±1% | 4210 K | 0.12 mA |
| 100 kΩ | NTC0402X104[F/H/J]3950FB | 3950 K ±1% | 3987 K | 0.10 mA |
| 100 kΩ | NTC0402X104[F/H/J]4250FB | 4250 K ±1% | 4310 K | 0.10 mA |
| 470 kΩ | NTC0402X474[F/J]4050FA | 4000 K ±1% | 4050 K ±1% | 0.04 mA |
[F/H/J] denotes three listed R25-tolerance variants; [F/J] denotes the two variants listed for 470 kΩ. Brackets are not part of an orderable code. Tolerance placement follows the source table exactly.
| Parameter | Specified value | Condition or interpretation |
|---|---|---|
| Dissipation factor | 1.0 mW/°C | Power required to raise body temperature by 1 °C under the defined condition. |
| Thermal time constant | <3 s | 63.2% response under the specified method; not a finished-system guarantee. |
| Rated power | 100 mW at 25 °C | Associated with a 100 °C self-heating rise in the specification definition. |
| Operating ambient | −40 °C to +125 °C | Do not operate beyond this range. |
| Body length L | 1.00 ±0.15 mm | 0.039 ±0.006 in |
| Body width W | 0.50 ±0.15 mm | 0.020 ±0.006 in |
| Body thickness T | 0.50 ±0.15 mm | 0.020 ±0.006 in |
| Terminal dimension a | 0.25 ±0.10 mm | 0.010 ±0.004 in |
| Recommended land A | 0.45 to 0.55 mm | Dimension A in the controlled land-pattern drawing. |
| Recommended land B / C | 0.40 to 0.50 mm / 0.45 to 0.55 mm | Validate paste aperture, placement and solder-joint quality. |
PCB Land Pattern, Soldering, Reliability, Packing, and Storage
Reflow Soldering Window
- Ramp: 1 to 2 °C/s.
- Preheat: 150 to 170 °C for 90 ±30 s.
- Time above 240 °C: 20 to 40 s.
- Peak: 260 °C maximum for 10 s.
- Maximum reflow cycles: two.
- Specified solder: 96.5Sn / 3.0Ag / 0.5Cu.
Manual Soldering Boundary
The specification limits the iron to 20 W, requires preheating at 150 °C for 60 s, limits the tip to 280 °C and 3 s, and permits one operation. Do not touch the terminal electrodes with the tip.
Reliability Test Conditions
| Test | Condition | Requirement shown in the specification |
|---|---|---|
| Terminal strength | 5 N for 10 ±1 s | No terminal removal, ceramic split or other defect. |
| Board flexure | 2 mm; press speed <0.5 mm/s; 10 ±1 s | No visible damage; |ΔR25/R25| ≤2%. |
| Vibration | 10–55 Hz; 1.5 mm total amplitude; 2 h in each of three axes | No visible damage. |
| Drop | 1 m onto concrete, 10 times | No visible damage. |
| Solderability | 245 ±5 °C for 3 ±0.3 s | At least 95% wetting coverage. |
| Soldering heat | 260 ±5 °C for 10 ±1 s | No visible damage; |ΔR25/R25| ≤2%; |ΔB/B| ≤1%. |
| Temperature cycling | Five cycles: −40 ±5 °C / 25 ±2 °C / 125 ±2 °C / 25 ±2 °C with specified dwell times | No visible damage; |ΔR25/R25| ≤2%; |ΔB/B| ≤1%. |
| Dry heat / cold storage | 125 ±5 °C for 1000 ±24 h / −40 ±3 °C for 1000 ±24 h | No visible damage; |ΔR25/R25| ≤2%; |ΔB/B| ≤1%. |
| Damp heat | 40 ±2 °C; 90% to 95% RH; 1000 ±24 h | No visible damage; |ΔR25/R25| ≤2%; |ΔB/B| ≤1%. |
| High-temperature load | 85 ±2 °C; permissible current; 1000 ±48 h | No visible damage; |ΔR25/R25| ≤2%; |ΔB/B| ≤1%. |
Where specified, stabilize samples for 1 to 2 hours under normal conditions before measurement.
Packing and Storage
NTC0402 is supplied on 8.0 ±0.3 mm paper carrier tape, 10,000 units per reel. Tape thickness is 0.5 ±0.15 mm; component pitch is 4.0 ±0.1 mm. The reel outer diameter is 178 ±2 mm and hub diameter is 58 ±2 mm. Store at −10 °C to +40 °C and ≤75% RH, protected from dust, corrosive atmosphere and direct sunlight. The stated storage period is six months.
Application Guidance and Design Limitations
The specification does not grant application-specific approval. The following are potential categories requiring complete circuit, thermal, mechanical, environmental, assembly and safety qualification.
Compact PCB temperature sensingValidate heat spreading, local hot spots, solder symmetry and the offset between board and target temperature.
Battery and power monitoringDefine the thermal interface and diagnostics. The thermistor alone does not disconnect power or provide a certified safety function.
Portable and space-constrained electronicsQualify moisture protection, board flex, handling and excitation duty cycle in the final product.
Temperature compensationUse a validated R–T model, placement and calibration that satisfy the circuit error budget.NTC0402 Engineering FAQs
What is the NTC0402 Series?
NTC0402 is a passive, two-terminal, surface-mount negative-temperature-coefficient (NTC) thermistor series. The controlled body dimensions are 1.00 ±0.15 mm × 0.50 ±0.15 mm × 0.50 ±0.15 mm, and resistance decreases as temperature increases.
What does “0402” mean in NTC0402?
“0402” is the imperial package designation; the corresponding metric designation is 1005. For mechanical design, use the controlled dimensions and tolerances rather than the package name alone.
Is NTC0402 a digital temperature sensor?
No. It has no supply pin, address, protocol, register map or digital output. The external circuit measures resistance and performs temperature conversion.
Which NTC0402 resistance values are listed?
The specification lists 10 kΩ, 22 kΩ, 33 kΩ, 47 kΩ, 68 kΩ, 100 kΩ and 470 kΩ nominal R25 values. Use a complete listed part number because available B characteristics and tolerance combinations differ.
Which B constant should be used?
Use the B constant and calculation interval assigned to the exact orderable part number. The final “A” code denotes a 25 °C/85 °C interval, while “B” denotes 25 °C/50 °C. Do not interchange B25/50 and B25/85, and do not assign a tolerance where the electrical table does not state one.
How are R25 and the B constant measured?
R25 is measured at 25 ±0.05 °C with measuring power not exceeding 0.1 mW. The nominal B constant is calculated from resistance measured at 25 ±0.05 °C and at either 50 ±0.05 °C or 85 ±0.05 °C, according to the interval identified by the part number.
Is the 470 kΩ version available with ±3% R25 tolerance?
No such combination is listed in this product specification. The 470 kΩ configuration appears as ±1% and ±5% R25 variants only.
What permissible operating current is specified at 25 °C?
The listed permissible operating current ranges from 0.31 mA for the 10 kΩ configurations to 0.04 mA for the 470 kΩ configuration. The specification defines this current as the value that raises the temperature of a PCB-mounted thermistor body by 1 °C through self-heating in still air. It is a specified limit under that condition, not a universal recommended measurement current. Precision sensing circuits should normally use lower or duty-cycled excitation and verify self-heating in the final assembly.
What is the specified NTC0402 thermal time constant?
The product specification lists a thermal time constant of less than 3 s. It is defined as the time required for the thermistor temperature to complete 63.2% of the change between the initial and final ambient temperatures after the applied power changes from a non-zero-power state to a zero-power state. Response in the finished product also depends on PCB copper, solder joints, coating, airflow, enclosure and thermal contact.
Can the 100 mW rated power be used as the measurement power?
No. The specification defines 100 mW at 25 °C as the power required to raise the thermistor temperature by 100 °C through self-heating. It is not a recommended measurement level. Select excitation power from the allowable self-heating error and verify it in the final thermal environment.
What PCB land pattern is recommended?
The specification shows A = 0.45 to 0.55 mm, B = 0.40 to 0.50 mm and C = 0.45 to 0.55 mm. Validate paste aperture, placement accuracy, solder symmetry and tombstoning risk.
Can NTC0402 replace any 0402 thermistor with the same R25?
Not automatically. Match R25 and tolerance, B value and interval, R–T behavior, ratings, body and land dimensions, assembly process and qualification requirements.
What reflow-soldering profile is specified?
The specification gives a 1 to 2 °C/s ramp, a 150 to 170 °C preheat for 90 ±30 s, 20 to 40 s above 240 °C, and a maximum peak of 260 °C for 10 s, with no more than two reflow cycles. The stated solder alloy is 96.5Sn/3.0Ag/0.5Cu.
How should NTC0402 be stored?
Store at −10 °C to +40 °C and ≤75% RH, away from dust, corrosive atmosphere and sunlight. The specification states a six-month storage period.
This page summarizes the NYFEA NTC0402 Series product specification for selection and engineering evaluation. It does not replace the controlled PDF. Before production release, confirm revision, exact part number, R25 and B data, test conditions, dimensions, land pattern, soldering, reliability, packing, storage and final application qualification.
