DO-41 Standard Series - Glass Encapsulated Thermistors (300°C)

Littelfuse Leaded Thermistors DO-41 Standard image
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Littelfuse products are not designed for, and shall not be used for, any purpose (including, without limitation, automotive, military, aerospace, medical, life-saving, life-sustaining or nuclear facility applications, devices intended for surgical implant into the body, or any other application in which the failure or lack of desired operation of the product may result in personal injury, death, or property damage) other than those expressly set forth in applicable Littelfuse product documentation. Warranties granted by Littelfuse shall be deemed void for products used for any purpose not expressly set forth in applicable Littelfuse documentation. Littelfuse shall not be liable for any claims or damages arising out of products used in applications not expressly intended by Littelfuse as set forth in applicable Littelfuse documentation. The sale and use of Littelfuse products is subject to Littelfuse Terms and Conditions of Sale, unless otherwise agreed by Littelfuse. "Littelfuse" includes Littelfuse, Inc., and all of its affiliate entities.

Littelfuse low cost glass encapsulated thermistors are manufactured using super stable NTC chips which are hermetically sealed in a glass (DO-41 diode style) package. The result is a device which exhibits excellent long term reliability and stability even when subjected to severe environmental or thermal conditions. Their uniform dimensions and axial lead configuration make them especially suitable for use with automatic insertion equipment.


  • High temperature capability to +300°C
  • Hermetically sealed glass package
  • Low cost
  • Excellent long-term stability
  • High voltage insulation
  • Tinned CCS lead wires are solderable or weldable


  • Non-standard resistance values and tolerances
  • Point matched at specified temperatures
  • Tape and reel packaging


  • Thermal time constant: 8 seconds max (still air)
  • Thermal time constant: 2 seconds max (stirred liquid)
  • Dissipation constant: 3 mW/°C (still air)

Access specifications, certifications, check availability and order parts below

Catalog #Resis Ω @ 25°CResis Tol ± % @25°CR-T CurveOperating TemperatureEngineering DrawingRT TableStockSamplesCompare
101BH1K10010B-55° to 220°CEngineeringRT
102FH1K100010F-55° to 300°CEngineeringRTCheckOrder
202JH1K200010J-55° to 300°CEngineeringRTCheck
203RH1K2000010R-55° to 300°CEngineeringRTCheck
222JH1K225210J-55° to 300°CEngineeringRTCheck
302JH1K300010J-55° to 300°CEngineeringRTCheckOrder
333RH1K3300010R-55° to 300°CEngineeringRTCheck
501FH1K50010F-55° to 300°CEngineeringRTCheckOrder
502JH1K500010J-55° to 300°CEngineeringRTCheck
Part # Part Description RoHS Pb-free RoHS (2015/ 863/EU) Certificate REACH (SVHC’s) Declaration Halogen Free REACH (SVHC’s) IPC-Material Declaration
501FH1K THERMISTOR, US SENSOR P/ RoHS No 02/13/2019 PbFree No
502JH1K NTC THERMISTOR 5K OHM 10% DO41 RoHS No 02/13/2019 PbFree No
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