GS103G1K NTC Thermistor 10kΩ Equivalent & Substitute Parts

Part Overview

The GS103G1K is an NTC thermistor manufactured by Littelfuse Inc., featuring a 10kΩ resistance at 25°C in a glass bead package with 1.00" lead wire length. This component is classified as obsolete, making identification of suitable substitute parts essential for ongoing design support and procurement continuity. The GS103G1K operates at temperatures up to 250°C and is suitable for through-hole mounting applications requiring temperature sensing functionality.

Substiute Parts

GS103G1K

Littelfuse Inc.In Stock: 911GS103G1K Datasheet

Current PartRFQ

112-103FAJ-B01

Honeywell Sensing and Productivity SolutionsIn Stock: 817112-103FAJ-B01 Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the GS103G1K is determined by the following critical parameters:

• Resistance value at 25°C: 10kΩ (primary electrical specification)
• B-value thermal characteristic (B25/85): 3694K (defines temperature response curve)
• Package type: Glass bead (mechanical and thermal interface requirement)
• Operating temperature capability: Minimum 250°C support
• Mounting configuration: Through-hole compatible

The substitute part 112-103FAJ-B01 maintains functional equivalence through matching resistance value, comparable B-value thermal response, identical package type, and compatible operating temperature range. Variations in lead wire length and tolerance specifications are secondary considerations that do not prevent functional substitution in most applications.

Parameter Comparison

Engineering Selection Recommendations

The 112-103FAJ-B01 serves as a direct functional substitute for the obsolete GS103G1K based on the following criteria:

• Both components maintain 10kΩ nominal resistance at 25°C, ensuring electrical compatibility in circuit designs
• B25/85 thermal values are within 0.7% of each other (3694K vs 3669K), providing equivalent temperature response characteristics for thermistor applications
• Glass bead package construction is identical, maintaining thermal coupling and mechanical interface properties
• The 112-103FAJ-B01 operates across an extended temperature range (-60°C to 300°C), fully encompassing the GS103G1K operating window
• Active product status and RoHS compliance of the 112-103FAJ-B01 provide long-term supply assurance and regulatory alignment

Lead wire length differs between the two parts (1.00" vs 0.38"), requiring mechanical layout verification during integration. Resistance tolerance specification is wider for the substitute (±20% vs ±10%), which may require circuit design review in applications with tight tolerance requirements.

Frequently Asked Questions (FAQ)

Q: Can the 112-103FAJ-B01 directly replace the GS103G1K in existing designs?

A: Electrical substitution is valid based on matching 10kΩ resistance and comparable B-value thermal response. Physical integration requires verification of lead wire length compatibility, as the substitute features shorter leads (0.38" vs 1.00").

Q: What is the significance of the B25/85 value in thermistor selection?

A: The B25/85 value defines the thermistor's thermal response curve between 25°C and 85°C. The GS103G1K (3694K) and 112-103FAJ-B01 (3669K) values are within 0.7%, ensuring functionally equivalent temperature sensing behavior across the operating range.

Q: Does the wider resistance tolerance of the 112-103FAJ-B01 affect circuit performance?

A: The substitute part tolerance is ±20% compared to the original ±10%. Applications requiring precise resistance values at 25°C should evaluate whether this tolerance range remains acceptable for the intended circuit function.

Q: Is the extended operating temperature range of the 112-103FAJ-B01 a concern?

A: No. The substitute's -60°C to 300°C range fully encompasses the GS103G1K maximum of 250°C, providing equivalent or superior thermal capability.

Q: What mounting differences exist between these parts?

A: The GS103G1K is specified for through-hole mounting, while the 112-103FAJ-B01 is free-hanging. Both use identical glass bead packages and are compatible with through-hole PCB applications; mounting method differences do not prevent functional substitution.

Q: Does RoHS compliance of the substitute affect compatibility?

A: RoHS compliance of the 112-103FAJ-B01 indicates adherence to hazardous substance restrictions, providing regulatory advantage. This does not affect electrical or thermal compatibility with the original part.