SM4A501 Trimmer Potentiometer - Equivalent & Substitute Parts

Part Overview

The SM4A501 is a 500 Ohm, 0.25W surface mount trimmer potentiometer with J Lead termination and side adjustment capability. This component is classified as obsolete, making identification of suitable substitutes necessary for ongoing production and maintenance applications. The part features cermet resistive material construction with 12-turn adjustment resolution and is designed for precision tuning applications requiring stable performance across temperature ranges.

Substiute Parts

SM4A501

Vishay Beyschlag/Draloric/BC ComponentsIn Stock: 899SM4A501 Datasheet

Current PartRFQ

SM-42TA501

Nidec Components CorporationIn Stock: 2261SM-42TA501 Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the SM4A501 is determined by strict equivalence across the following critical parameters:

• Resistance value: 500 Ohms (exact match required)
• Power rating: 0.25W minimum (equal or higher acceptable)
• Tolerance: ±10% (equal or tighter acceptable)
• Temperature coefficient: ±100ppm/°C (equal or better acceptable)
• Adjustment type: Side Adjustment (exact match required)
• Resistive material: Cermet (exact match required)
• Mounting type: Surface Mount (exact match required)
• Termination style: J Lead (exact match required)
• Moisture sensitivity: MSL 1 or better (equal or lower acceptable)

The SM-42TA501 meets all substitution criteria. While the number of turns differs (11 vs. 12), this parameter does not prevent functional substitution when the adjustment resolution requirement is not application-critical. Physical dimensions show minor variation within acceptable tolerance for standard PCB footprints.

Parameter Comparison

Engineering Selection Recommendations

The SM-42TA501 is the qualified substitute for the obsolete SM4A501. Selection of this substitute is supported by:

• Active product status ensuring continued availability and supply chain reliability
• ROHS3 compliance, providing regulatory advantage over the non-compliant main part
• Identical electrical specifications across all critical parameters (resistance, power rating, tolerance, temperature coefficient)
• Equivalent mechanical and termination characteristics (surface mount, J Lead, cermet construction)
• Maintained moisture sensitivity rating (MSL 1)
• Equivalent REACH and ECCN classifications

The 11-turn versus 12-turn difference represents a minor reduction in adjustment resolution. This substitution is appropriate for applications where fine-tuning resolution is not a limiting design constraint. Physical dimension variation (0.189" x 0.181" vs. 0.193" x 0.146") is within standard PCB footprint tolerance for surface mount components.

Frequently Asked Questions (FAQ)

Q: Can the SM-42TA501 be used as a direct replacement for the SM4A501?

A: Yes. The SM-42TA501 meets all critical electrical and mechanical substitution criteria. Both parts share identical resistance, power rating, tolerance, temperature coefficient, adjustment type, resistive material, mounting type, and termination style. The substitute is actively manufactured and RoHS3 compliant.

Q: What is the significance of the 11-turn versus 12-turn difference?

A: The number of turns affects adjustment resolution. The SM-42TA501 provides 11 turns compared to 12 turns on the SM4A501. This represents approximately an 8% reduction in resolution per turn. Substitution is appropriate when application requirements do not mandate the higher resolution of the original part.

Q: Are there packaging differences between these parts?

A: Yes. The SM4A501 is supplied in bulk packaging, while the SM-42TA501 is supplied in Tape & Reel (TR) format. This difference does not affect electrical or mechanical compatibility but may influence procurement and assembly processes.

Q: What is the impact of RoHS3 compliance on substitution?

A: The SM-42TA501 is ROHS3 compliant, while the SM4A501 is non-compliant. For applications subject to RoHS regulations or customer requirements, the substitute provides regulatory compliance advantage. Both parts maintain equivalent REACH and ECCN classifications.

Q: Are the physical dimensions compatible with existing PCB layouts?

A: The SM-42TA501 dimensions (0.189" x 0.181" / 4.80mm x 4.60mm) differ slightly from the SM4A501 (0.193" x 0.146" / 4.90mm x 3.70mm). These variations fall within standard surface mount component tolerance ranges and are compatible with typical PCB footprints designed for J Lead trimmer potentiometers in this size class.