ROX1SF120K Equivalent & Substitute Parts

Part Overview

The ROX1SF120K is a 120 kOhms ±1% 1W axial through-hole resistor manufactured by TE Connectivity Passive Product. This component features metal oxide film construction with flame-proof and pulse-withstanding characteristics, designed for applications requiring safety-rated passive components. The product is currently obsolete, necessitating identification of functionally equivalent alternatives that maintain electrical and mechanical compatibility with existing designs.

Substiute Parts

ROX1SF120K

TE Connectivity Passive ProductIn Stock: 1165ROX1SF120K Datasheet

Current PartRFQ

FMF1WSFRF52-120K

YAGEOIn Stock: 1248FMF1WSFRF52-120K Datasheet

DirectRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the ROX1SF120K is determined by strict equivalence across the following critical parameters:

Electrical Parameters:

• Resistance value: 120 kOhms
• Tolerance: ±1%
• Power rating: 1W

Mechanical Parameters:

• Package type: Axial through-hole
• Physical dimensions compatible with PCB layouts designed for the original component

Functional Parameters:

• Flame-proof construction
• Safety-rated characteristics
• Operating temperature range compatibility

The FMF1WSFRF52-120K from YAGEO meets these substitution criteria. While the substitute employs metal film composition rather than metal oxide film, and exhibits different temperature coefficient and maximum operating temperature specifications, it maintains electrical equivalence in resistance, tolerance, and power rating. The substitute is physically smaller and utilizes metal film technology, which represents a functional upgrade in terms of temperature stability and operating range extension.

Parameter Comparison

Engineering Selection Recommendations

The FMF1WSFRF52-120K is the designated equivalent substitute for the obsolete ROX1SF120K. Selection of this substitute is based on the following engineering criteria:

Electrical Equivalence: Both components provide identical resistance (120 kOhms) and tolerance (±1%) specifications, ensuring circuit performance equivalence in applications where these parameters are critical.

Mechanical Compatibility: Both components utilize axial through-hole packaging. The substitute is physically smaller, which provides layout flexibility. PCB designs accommodating the original component dimensions will accept the substitute without modification.

Product Status: The FMF1WSFRF52-120K is an active product with current manufacturing support, addressing the obsolescence of the original component.

Compliance: The substitute is ROHS3 compliant and REACH unaffected, meeting current regulatory requirements for electronic component procurement.

Performance Characteristics: The substitute exhibits superior temperature stability (±100ppm/°C versus ±350ppm/°C) and extended maximum operating temperature (155°C versus 130°C), representing functional improvements over the original specification.

Frequently Asked Questions (FAQ)

Q: Can the FMF1WSFRF52-120K directly replace the ROX1SF120K in existing designs?

A: Yes. Both components share identical electrical specifications (120 kOhms, ±1%, 1W) and axial through-hole packaging. The substitute is physically smaller, which does not prevent installation in PCB layouts designed for the original component.

Q: What is the difference between metal oxide film and metal film composition?

A: Metal oxide film resistors, as used in the ROX1SF120K, are constructed by depositing a metal oxide layer on a ceramic substrate. Metal film resistors, as used in the FMF1WSFRF52-120K, employ a thin metal alloy film on a ceramic core. Metal film construction typically provides superior temperature stability and tighter tolerance performance.

Q: Does the substitute meet the same safety and flame-proof requirements?

A: The FMF1WSFRF52-120K is specified as flame-proof and safety-rated. Both components are designed for applications requiring safety-rated passive components.

Q: What is the significance of the temperature coefficient difference?

A: The FMF1WSFRF52-120K exhibits a temperature coefficient of ±100ppm/°C compared to ±350ppm/°C for the ROX1SF120K. This indicates the substitute maintains more stable resistance values across temperature variations, representing improved performance in temperature-sensitive applications.

Q: Are there packaging differences between the two components?

A: The ROX1SF120K is supplied in standard packaging, while the FMF1WSFRF52-120K is supplied in Tape & Reel (TR) format. Both are through-hole axial components suitable for PCB assembly. The substitute's smaller physical dimensions (0.130" Dia x 0.354" L versus 0.138" Dia x 0.394" L) provide layout advantages without affecting functional compatibility.

Q: Is the substitute RoHS compliant?

A: Yes. The FMF1WSFRF52-120K is ROHS3 compliant, meeting current environmental and regulatory requirements for electronic component procurement.