LR1F1K78 Equivalent & Substitute Parts

Part Overview

The LR1F1K78 is a 1.78 kOhms ±1% 0.6W through hole resistor manufactured by TE Connectivity Passive Product in the Neohm series. This axial metal film resistor is designed for general-purpose applications requiring precision resistance values with tight tolerance specifications. The part is currently in active production status with 726 units available in inventory. Substitute parts are identified when the main part becomes unavailable, when procurement lead times are extended, or when alternative sourcing is required to optimize supply chain efficiency while maintaining equivalent electrical and mechanical performance.

Substiute Parts

LR1F1K78

TE Connectivity Passive ProductIn Stock: 775LR1F1K78 Datasheet

Current PartRFQ

MRS25000C1781FCT00

Vishay Beyschlag/Draloric/BC ComponentsIn Stock: 6633MRS25000C1781FCT00 Datasheet

DirectRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the LR1F1K78 is determined by matching the following critical electrical and mechanical parameters:

• Resistance Value: 1.78 kOhms (exact match required)
• Tolerance: ±1% (exact match required)
• Power Rating: 0.6W (exact match required)
• Composition: Metal Film (exact match required)
• Temperature Coefficient: ±50ppm/°C (exact match required)
• Operating Temperature Range: -55°C ~ 155°C (exact match required)
• Package Configuration: Axial through hole (exact match required)
• Termination Count: 2 (exact match required)
• Compliance: ROHS3 Compliant (exact match required)

The MRS25000C1781FCT00 manufactured by Vishay Beyschlag/Draloric/BC Components meets all substitution criteria. Both parts are metal film axial resistors with identical electrical specifications, operating ranges, and regulatory compliance status. Physical dimensions vary slightly between manufacturers, which is acceptable within industry standards for axial through hole components.

Parameter Comparison

Engineering Selection Recommendations

Both the LR1F1K78 and MRS25000C1781FCT00 are active production components with full ROHS3 compliance and identical electrical performance specifications. Selection between these parts is based on the following factors:

LR1F1K78 (TE Connectivity): Select this part when TE Connectivity sourcing is preferred, when Tape & Box packaging is required for assembly operations, or when existing supply agreements specify TE Connectivity components.

MRS25000C1781FCT00 (Vishay): Select this part when Vishay sourcing is preferred, when Cut Tape packaging is acceptable for assembly processes, or when Vishay components are already qualified in the supply chain. This part has higher inventory availability (6531 units) compared to the TE Connectivity alternative.

Both parts are suitable for applications operating within the -55°C to 155°C temperature range and requiring 1% tolerance precision resistors. The minor dimensional variations between the two axial packages do not affect electrical performance or standard PCB footprint compatibility for through hole mounting.

Frequently Asked Questions (FAQ)

Q: Can MRS25000C1781FCT00 be used as a direct replacement for LR1F1K78?

A: Yes. Both parts have identical electrical specifications including resistance value, tolerance, power rating, temperature coefficient, and operating temperature range. The axial package configuration and through hole termination are compatible with the same PCB footprints. Minor physical dimension differences are within acceptable tolerances for axial through hole components.

Q: What is the difference between Tape & Box and Cut Tape packaging?

A: Tape & Box (TB) packaging includes a full reel of components on tape with a protective box. Cut Tape (CT) packaging provides components on tape segments cut to specific quantities. Both formats are suitable for automated assembly equipment. Selection depends on assembly line requirements and inventory management preferences.

Q: Are there any compliance differences between these parts?

A: No. Both parts are ROHS3 compliant and carry the same ECCN (EAR99) and HTSUS (8533.21.0090) classifications. Both are classified as ROHS3 Compliant with Not Applicable moisture sensitivity levels.

Q: Do the dimensional differences affect circuit performance?

A: No. The dimensional variations (0.091" vs 0.098" diameter and 0.244" vs 0.256" length) are minor manufacturing tolerances between different manufacturers. These differences do not affect electrical performance, frequency response, or thermal characteristics. Both parts fit standard axial resistor footprints on PCBs.

Q: Which part should be selected for new designs?

A: Either part is acceptable for new designs. Selection should be based on supply chain strategy, preferred manufacturer relationships, packaging requirements, and inventory availability. Both parts offer equivalent performance and reliability for the specified application range.

Q: What is the temperature coefficient significance?

A: The ±50ppm/°C temperature coefficient indicates that the resistance value changes by approximately 50 parts per million for each degree Celsius change in operating temperature. Both parts have identical temperature coefficients, ensuring equivalent performance across the -55°C to 155°C operating range.