ST-42ETA203 Equivalent & Substitute Parts

Part Overview

The ST-42ETA203 is a 20 kOhms surface mount trimmer potentiometer manufactured by Nidec Components Corporation. This 0.25W cermet trimmer features J lead termination with top adjustment capability and is designed for applications requiring precision resistance tuning in compact form factors. The part is currently active in production with full RoHS3 compliance and unlimited moisture sensitivity rating. Substitute parts are identified when equivalent electrical specifications, mechanical dimensions, and environmental certifications align with the original component requirements.

Substiute Parts

ST-42ETA203

Nidec Components CorporationIn Stock: 1077ST-42ETA203 Datasheet

Current PartRFQ

23AR20KLFTR

TT Electronics/BIIn Stock: 886623AR20KLFTR Datasheet

SimilarRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitute parts for the ST-42ETA203 are qualified based on strict equivalence across the following critical parameters:

• Resistance value: 20 kOhms
• Power rating: 0.25W (1/4W)
• Tolerance: ±20%
• Temperature coefficient: ±100ppm/°C
• Number of turns: 1 turn
• Adjustment type: Top adjustment
• Resistive material: Cermet
• Mounting type: Surface mount
• Termination style: J lead
• Physical dimensions: 0.197" x 0.177" face (5.00mm x 4.50mm)
• Packaging format: Tape & Reel

The 23AR20KLFTR from TT Electronics/BI meets all specified electrical and mechanical parameters, enabling direct substitution in applications where the ST-42ETA203 is designated.

Parameter Comparison

Engineering Selection Recommendations

Both the ST-42ETA203 and 23AR20KLFTR are active production components with full compliance to environmental and regulatory standards. The ST-42ETA203 carries RoHS3 certification, while the 23AR20KLFTR carries RoHS compliance. Both parts maintain unlimited moisture sensitivity ratings and are classified under the same ECCN and HTSUS codes, confirming regulatory equivalence. Selection between these parts may be based on supply availability, lead time, or procurement preferences, as electrical and mechanical specifications are identical.

Frequently Asked Questions (FAQ)

Q: Can the 23AR20KLFTR replace the ST-42ETA203 in existing designs?

A: Yes. The 23AR20KLFTR meets all electrical specifications (20 kOhms, 0.25W, ±20% tolerance, ±100ppm/°C temperature coefficient), mechanical dimensions (0.197" x 0.177" face), and termination requirements (J lead, top adjustment, surface mount) of the ST-42ETA203. Both parts are packaged in Tape & Reel format and carry equivalent environmental certifications.

Q: Are there differences in RoHS compliance between these parts?

A: The ST-42ETA203 is RoHS3 compliant, while the 23AR20KLFTR is RoHS compliant. Both meet current regulatory requirements for lead-free and restricted substance compliance. The difference in designation reflects manufacturer certification timelines and does not affect functional equivalence.

Q: What is the significance of the 1-turn specification?

A: The 1-turn specification indicates that the trimmer potentiometer requires one complete rotation to traverse the full resistance range from minimum to maximum. This parameter must match exactly for functional equivalence, as multi-turn trimmers provide finer adjustment resolution and are not interchangeable with 1-turn designs.

Q: Does the J lead termination affect PCB layout considerations?

A: J lead termination is a surface mount configuration suitable for standard reflow soldering processes. Both the ST-42ETA203 and 23AR20KLFTR use identical J lead geometry and footprint dimensions (0.197" x 0.177" face, 5.00mm x 4.50mm), requiring no PCB layout modifications when substituting between these parts.

Q: What does the ±100ppm/°C temperature coefficient mean for application stability?

A: The temperature coefficient specifies the resistance change per degree Celsius across the operating temperature range. A ±100ppm/°C rating indicates that resistance will vary by approximately 0.01% per degree Celsius. This parameter must remain constant for applications requiring stable tuning across temperature extremes, and both parts meet this specification identically.