NF08AA0509M Inrush Current Limiter - Equivalent & Substitute Parts

Part Overview

The NF08AA0509M is an inrush current limiter manufactured by KYOCERA AVX, rated at 5 Ohms ±20% with a maximum steady-state current of 3.4 A and a physical diameter of 0.315" (8.00mm). This component is classified as obsolete, making identification of suitable substitute parts essential for ongoing system support and procurement planning. The NF08 series is no longer in active production, necessitating evaluation of alternative components that maintain functional equivalence within the specified electrical and mechanical parameters.

Substiute Parts

NF08AA0509M--

KYOCERA AVXIn Stock: 832NF08AA0509M-- Datasheet

Current PartRFQ

B57153S0479M000

EPCOS - TDK ElectronicsIn Stock: 31841B57153S0479M000 Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the NF08AA0509M is determined by the following critical parameters:

• Resistance Value: 5 Ohms nominal with ±20% tolerance establishes the functional operating point
• Steady-State Current Rating: 3.4 A maximum defines the thermal and electrical load capacity
• Physical Diameter: 0.315" (8.00mm) constrains mechanical fit within the assembly
• Lead Spacing: 0.300" (7.62mm) determines PCB footprint compatibility
• Tolerance Class: ±20% defines acceptable resistance variation

The substitute part B57153S0479M000 (EPCOS - TDK Electronics, S153 series) provides functional equivalence through comparable electrical characteristics and active product status, enabling continued system support despite the obsolescence of the original component.

Parameter Comparison

Engineering Selection Recommendations

Selection of B57153S0479M000 as a substitute for NF08AA0509M is supported by the following factors:

• Active Product Status: The substitute is actively manufactured by EPCOS - TDK Electronics, ensuring long-term availability and supply chain continuity
• Electrical Equivalence: The 4.7 Ohm resistance value falls within the ±20% tolerance specification of the original 5 Ohm component, maintaining functional performance within design margins
• Regulatory Compliance: The substitute meets ROHS3 compliance requirements, whereas the original component is non-compliant, aligning with current environmental and procurement standards
• Certification: UL approval on the substitute provides third-party validation of electrical safety characteristics
• Current Rating Consideration: The substitute is rated at 3 A steady-state maximum, compared to 3.4 A for the original. Applications operating near the upper limit of the original specification require verification that the reduced rating remains acceptable

Critical Design Verification: The lead spacing reduction from 0.300" (7.62mm) to 0.197" (5.00mm) necessitates PCB layout review to confirm mechanical compatibility with existing footprints. The diameter increase from 0.315" (8.00mm) to 0.335" (8.50mm) should be evaluated for clearance within the mechanical assembly.

Frequently Asked Questions (FAQ)

Q: Can B57153S0479M000 be used as a direct replacement for NF08AA0509M?

A: Electrical substitution is valid based on resistance value and tolerance equivalence. However, mechanical compatibility must be verified due to differences in lead spacing (0.197" vs. 0.300") and diameter (0.335" vs. 0.315"). PCB layout and mechanical clearance review is required before implementation.

Q: What is the significance of the resistance value difference (4.7 Ohms vs. 5 Ohms)?

A: The 4.7 Ohm value of the substitute falls within the ±20% tolerance band of the original 5 Ohm specification. Both components operate within the same functional envelope for inrush current limiting applications. The actual operating point depends on circuit design and load characteristics.

Q: Does the lower current rating (3 A vs. 3.4 A) affect substitution suitability?

A: Applications must be evaluated individually. If the design operates below 3 A steady-state current, the substitute is suitable. If the application requires the full 3.4 A capacity, the reduced rating of the substitute may not be acceptable. Thermal analysis and load profiling are necessary to confirm compatibility.

Q: Why is lead spacing different between the two components?

A: Lead spacing is determined by the mechanical design of each manufacturer's component series. The S153 series uses a 0.197" (5.00mm) spacing, while the NF08 series uses 0.300" (7.62mm). PCB footprint modification or component repositioning may be required for mechanical fit.

Q: What is the advantage of the substitute's ROHS3 compliance?

A: ROHS3 compliance indicates the substitute meets current environmental regulations restricting hazardous substances. This supports regulatory compliance for new designs and procurement policies aligned with modern environmental standards. The original NF08AA0509M, being non-compliant, may face procurement restrictions in regulated markets.

Q: Are there any moisture sensitivity considerations?

A: The original component has MSL 1 (Unlimited), indicating no moisture sensitivity constraints. The substitute lists MSL as Not Applicable, indicating equivalent or superior moisture handling characteristics. No additional moisture control measures are required for either component.