ST-2-20 Equivalent & Substitute Parts

Part Overview

The ST-2-20 is a laminated core power transformer manufactured by Signal Transformer, rated at 1.1VA with dual secondary windings. The primary winding accepts 115V input, while the secondary windings provide parallel 10V or series 20V output configurations. This transformer is designed for through-hole mounting with PC pin termination and is currently in active production status with 1140 units in stock.

Equivalent parts are identified when they maintain identical electrical performance specifications and mechanical compatibility within the allowed parameters for this transformer category.

Substiute Parts

ST-2-20

Signal TransformerIn Stock: 1150ST-2-20 Datasheet

Current PartRFQ

3FS-220

TamuraIn Stock: 10603FS-220 Datasheet

DirectRFQ

Key Parameters

Substitute Part Grouping Explanation

The 3FS-220 manufactured by Tamura qualifies as a direct substitute for the ST-2-20 based on the following matching parameters:

• Identical primary voltage: 115V
• Identical secondary voltage configuration: Parallel 10V, Series 20V
• Identical maximum output current: Parallel 110mA, Series 55mA
• Identical power rating: 1.1VA
• Identical core type: Laminated
• Identical winding configuration: Single primary, dual secondary, no center tap
• Identical mounting type: Through Hole
• Identical termination style: PC Pin
• Identical isolation voltage: 2500Vrms

Both parts operate within the same electrical and mechanical specifications, making them functionally interchangeable for applications requiring these exact parameters.

Parameter Comparison

Engineering Selection Recommendations

Both the ST-2-20 and 3FS-220 are active production components with full regulatory compliance. The ST-2-20 carries ROHS3 certification, while the 3FS-220 carries RoHS certification. Both are classified under ECCN EAR99 and share the same HTSUS code, confirming their equivalent classification for trade and regulatory purposes.

Selection between these parts should be based on availability, packaging preference (ST-2-20 supplied in box packaging with 1140 units in stock; 3FS-220 supplied in tube packaging with 990 units in stock), and minor dimensional variations. The 3FS-220 has slightly larger footprint dimensions (35.56mm L x 31.00mm W versus 34.90mm L x 28.60mm W) and greater seated height (25.40mm versus 24.60mm), which may impact PCB layout considerations in space-constrained applications.

Frequently Asked Questions (FAQ)

Q: Can the 3FS-220 replace the ST-2-20 in existing designs?

A: Yes. Both transformers maintain identical electrical specifications across all critical parameters: primary voltage, secondary voltage configuration, output current ratings, power rating, winding configuration, isolation voltage, and termination style. Mechanical compatibility is confirmed through identical mounting type and termination style. Minor dimensional differences should be evaluated against specific PCB layout constraints.

Q: What are the dimensional differences between these parts?

A: The ST-2-20 measures 34.90mm L x 28.60mm W with a maximum seated height of 24.60mm. The 3FS-220 measures 35.56mm L x 31.00mm W with a maximum seated height of 25.40mm. These differences are within typical manufacturing tolerances for laminated core transformers and should be verified against specific board layout requirements.

Q: Are there compliance differences between the ST-2-20 and 3FS-220?

A: Both parts are RoHS compliant and classified under the same ECCN (EAR99) and HTSUS (8504.31.4035) codes. The ST-2-20 carries ROHS3 certification while the 3FS-220 carries RoHS certification. Both meet isolation voltage requirements of 2500Vrms.

Q: What packaging formats are available?

A: The ST-2-20 is supplied in box packaging, while the 3FS-220 is supplied in tube packaging. Packaging selection may impact handling, storage, and integration into automated assembly processes.

Q: Are there inventory considerations for selecting between these parts?

A: The ST-2-20 has 1140 units in stock, while the 3FS-220 has 990 units in stock. Both maintain active production status, ensuring continued availability for future requirements.