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Contents

README

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QN0805X203J3950FB

QAMcn(恭成科技) · NTC Thermistors · 0805

QN0805X203J3950FB from QAMcn(恭成科技), in a 0805. 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 1 of an unpolarised resistor; either orientation.
2 2 passive Terminal 2 of an unpolarised resistor; either orientation.

Key specifications

Parameter Value
Manufacturer QAMcn(恭成科技)
Package 0805
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 (code J) R25 -5 5 % Tolerance code J = ±5% per part-numbering table 3
B constant tolerance (code F) B -1 1 % B-constant tolerance code F = ±1% per part-numbering table 3
Zero-power resistance at 25°C (R-T table, R_Min / R_Cent / R_Max) R25 19 20 21 Kohm 25°C; R-T table row 25, Res TOL 5.00% 13
Resistance at -40°C (R-T table) R 633.194 690.55 751.218 Kohm R-T table row -40 (R_Min / R_Cent / R_Max) 12
Resistance at 0°C (R-T table) R 61.61 65.628 69.733 Kohm R-T table row 0 (R_Min / R_Cent / R_Max) 12
Resistance at 85°C (R-T table) R 1.978 2.129 2.286 Kohm R-T table row 85 (R_Min / R_Cent / R_Max) 14
Resistance at 125°C (R-T table) R 0.626 0.682 0.741 Kohm R-T table row 125 (R_Min / R_Cent / R_Max) 15
Operating ambient temperature -40 125 ℃ Operating ambient temperature 3
Resistance change after resistance to soldering heat /ΔR25/R25/ -2 2 % After resistance to soldering heat test (260±5℃, 10±1 s); requirement /ΔR25/R25/ ≤ 2% 6
B constant change after resistance to soldering heat /ΔB/B/ -1 1 % After resistance to soldering heat test (260±5℃, 10±1 s); requirement /ΔB/B/ ≤ 1% 6
Thermal time constant 5 s Zero-power; time for 63.2% of temperature change (printed <5) 3
Zero-power resistance (nominal) R25 20 kΩ 25°C; measured at 25±0.05°C with power ≤0.1 mW 3
B constant (25/50°C) B 3950 K 25/50°C; measured at 25±0.05°C and 50±0.05°C 3
B constant (25/85°C) reference B 3987 K 25/85°C; printed as ref. value 3
Rated electric power 100 mW 25°C, still air; power that raises surface temperature by 100°C 3
Permissible operating current 2 mA 25°C, still air; current causing 1°C self-heating rise 3
Dissipation factor δ 0.32 mW/℃ 25°C still air; single unit without mounting; power to raise body temperature 1°C 3

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 5

CAD (KiCad official)

  • Symbol: QN0805X203J3950FB
  • Footprint: Resistor_SMD:R_0805_2012Metric
  • 3D model: 0805 (KiCad packages3D, STEP)
  • 3D model files: qn0805x203j3950fb-etched.step / qn0805x203j3950fb-etched.glb carry the MPN laser-etched on the die in a toggleable Adom.LaserEtch group (Fusion-ready); qn0805x203j3950fb.step / qn0805x203j3950fb.glb are the bare package body.

Provenance

Data extracted from the manufacturer datasheet, not a distributor listing:

  • Datasheet: QAMcn(恭成科技) datasheet (15 pp, sha256 948ce3556cc10635, retrieved 2026-10-17, 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, primary two-terminal convention (convention), consensus off (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).

Datasheet PDF