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CMFX 104F3950
Public Made by Adomby adom
Nanjing Shiheng Elec NTC Thermistors, 0402. Pinout cross-checked by two models against the datasheet, KiCad symbol/footprint/3D.
3D Model
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Symbol & Footprint
Schematic Symbol
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PCB Footprint
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Datasheet
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Contents
README
markdownCMFX 104F3950
Nanjing Shiheng Elec · NTC Thermistors · 0402
CMFX 104F3950 from Nanjing Shiheng Elec, in a 0402. Pinout and pin descriptions extracted from the manufacturer datasheet (extract_pins, cross-checked by a second model); symbol, footprint, and 3D from KiCad-official CAD.
Pinout
| Pin | Name | Type | Function |
|---|---|---|---|
| 1 | 1 | passive | Terminal electrode of the 100 kΩ ±1% (25 °C) B3950 chip NTC thermistor; non-polarized, interchangeable with the other terminal, operating range -40 to +125 °C. |
| 2 | 2 | passive | Terminal electrode of the 100 kΩ ±1% (25 °C) B3950 chip NTC thermistor; non-polarized, interchangeable with the other terminal, rated 100 mW at 25 °C. |
Key specifications
| Parameter | Value |
|---|---|
| Manufacturer | Nanjing Shiheng Elec |
| Package | 0402 |
| Category | Sensors |
| Pins | 2 |
Electrical characteristics
Limits as printed in the datasheet (page.json metadata.characteristics carries them as data).
| Parameter | Symbol | Min | Typ | Max | Unit | Conditions | Page |
|---|---|---|---|---|---|---|---|
| Resistance tolerance (R25), code F | R25 | -1 | 1 | % | Tolerance of resistance F ±1% (MPN suffix F) | 2 | |
| B constant tolerance (25/50), code F | B(25/50) | -1 | 1 | % | B constant 3950 ±1% | 2 | |
| Resistance at -40 ℃ (R-T table, R_Min/R_Cent/R_Max) | R | 3084.27 | 3225.55 | 3372.95 | kΩ | R-T table at -40 ℃; printed with thousands comma | 10 |
| Resistance at -20 ℃ (R-T table, R_Min/R_Cent/R_Max) | R | 922.616 | 953.185 | 984.67 | kΩ | R-T table at -20 ℃ | 10 |
| Resistance at 0 ℃ (R-T table, R_Min/R_Cent/R_Max) | R | 317.882 | 324.899 | 332.037 | kΩ | R-T table at 0 ℃ | 10 |
| Resistance at 25 ℃ (R-T table, R_Min/R_Cent/R_Max) | R | 99 | 100 | 101 | kΩ | R-T table at 25 ℃ | 11 |
| Resistance at 50 ℃ (R-T table, R_Min/R_Cent/R_Max) | R | 35.16 | 35.881 | 36.613 | kΩ | R-T table at 50 ℃ | 12 |
| Resistance at 85 ℃ (R-T table, R_Min/R_Cent/R_Max) | R | 10.172 | 10.509 | 10.856 | kΩ | R-T table at 85 ℃ | 12 |
| Resistance at 125 ℃ (R-T table, R_Min/R_Cent/R_Max) | R | 3.116 | 3.257 | 3.405 | kΩ | R-T table at 125 ℃ | 13 |
| Operating ambient temperature | -40 | 125 | ℃ | Operating ambient temperature range as printed | 2 | ||
| Storage temperature | -10 | 40 | ℃ | Storage; relative humidity ≦75%RH | 8 | ||
| Thermal time constant | 3 | s | Printed as <3 s; zero-power condition | 2 | |||
| Reflow peak temperature | 260 | ℃ | Reflow peak 260 ℃ max for 10 sec; max 2 reflow cycles | 9 | |||
| Iron soldering tip temperature | 280 | ℃ | Soldering iron tip 280 ℃ max, 3 sec max; max 1 time | 9 | |||
| Nominal zero-power resistance | R25 | 100 | kΩ | 25 ℃ | 2 | ||
| B constant (25/50) | B(25/50) | 3950 | K | 2 | |||
| B constant (25/85) | B(25/85) | 4010 | K | 2 | |||
| Permissible operating current | 0.1 | mA | 25 ℃ | 2 | |||
| Dissipation factor | 1 | mW/℃ | 2 | ||||
| Rated electric power | 100 | mW | 25 ℃ | 2 |
Materials and finish
As the datasheet states them (page.json metadata.appearance; the 3D model's colours follow it).
| Part | Material | Colour / plating | Datasheet says | Page |
|---|---|---|---|---|
| housing | PC | The current that keep body temperature of chip NTC on the PC board in still air | 4 |
CAD (KiCad official)
- Symbol:
CMFX 104F3950 - Footprint:
Resistor_SMD:R_0402_1005Metric - 3D model: 0402 (KiCad packages3D, STEP)
- 3D model files:
cmfx-104f3950-etched.step/cmfx-104f3950-etched.glbcarry the MPN laser-etched on the die in a toggleableAdom.LaserEtchgroup (Fusion-ready);cmfx-104f3950.step/cmfx-104f3950.glbare the bare package body.
Provenance
Data extracted from the manufacturer datasheet, not a distributor listing:
- Datasheet: Nanjing Shiheng Elec datasheet (13 pp, sha256
46ef8fb281e20992, retrieved 2026-10-18, tier: lcsc) - Datasheet language: Chinese. Pin names, descriptions, and specs on this page were extracted and translated to English by ds2sf; the linked PDF is the manufacturer original.
- Extractor: parts-factory
2.0.0/extract_pins 0.3, primaryclaude-sonnet-5-5(text+vision), consensusclaude-opus-5-5(agreed), guards: pin_guards 0.1: passed. Pins are checked against the footprint pad set and their cited datasheet pages before publish. - CAD: KiCad official libraries (CC-BY-SA 4.0).