Equivalent & Substitute Parts for 3FS-356 Laminated Power Transformer

Part Overview

The 3FS-356 is a laminated core power transformer manufactured by Tamura, rated at 2.4VA with dual secondary windings configured for parallel (28V, 90mA) or series (56V, 45mA) output. This through-hole mounted transformer is designed for Class 2/3 applications requiring 115V primary input with 2500Vrms isolation. The part is currently active in production with RoHS compliance and unlimited moisture sensitivity rating (MSL 1).

Substitute parts are identified when equivalent electrical performance, mechanical compatibility, and regulatory compliance can be maintained across different manufacturers while preserving form factor and termination standards.

Substiute Parts

3FS-356

TamuraIn Stock: 11573FS-356 Datasheet

Current PartRFQ

F56-045

Triad MagneticsIn Stock: 1239F56-045 Datasheet

SimilarRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the 3FS-356 is determined by strict equivalence across the following parameters:

Electrical Requirements:

• Primary voltage: 115V (single winding)
• Secondary voltage configuration: Dual windings supporting both 28V parallel and 56V series outputs
• Output current capacity: 90mA parallel / 45mA series minimum
• Power rating: 2.4VA or greater
• Isolation voltage: 2500Vrms minimum

Mechanical Requirements:

• Core type: Laminated construction
• Mounting: Through-hole technology
• Termination: PC pin style
• Physical envelope: Compatible with 35.56mm L × 31.00mm W × 32.10mm H (seated) or smaller

Regulatory Requirements:

• RoHS compliance (RoHS 2 or RoHS 3)
• ECCN classification: EAR99
• HTSUS code: 8504.31.4035

The substitute part F56-045 (Triad Magnetics) meets all critical electrical, mechanical, and regulatory criteria for direct substitution in the 3FS-356 application.

Parameter Comparison

Engineering Selection Recommendations

Primary Part: 3FS-356 (Tamura)

The 3FS-356 remains the specified component with active production status and confirmed inventory of 1144 units. Selection of this part is appropriate when Tamura supply chain continuity and existing design validation are priorities.

Substitute Part: F56-045 (Triad Magnetics)

The F56-045 qualifies as a direct electrical and mechanical substitute based on:

• Identical primary and secondary voltage specifications
• Matching output current ratings for both parallel and series configurations
• Equal or superior power rating (2.5VA vs. 2.4VA)
• Equivalent isolation voltage (2500Vrms)
• Identical core type, winding configuration, and termination style
• Smaller physical footprint (34.93mm L × 28.58mm W × 30.15mm H) provides layout flexibility
• ROHS3 compliance exceeds RoHS 2 requirements
• Matching ECCN and HTSUS classifications
• Active production status with confirmed inventory of 1156 units

Selection of F56-045 is appropriate when Triad Magnetics supply availability is preferred, when reduced board space is beneficial, or when supply chain diversification is required.

Frequently Asked Questions (FAQ)

Q: Can F56-045 be used as a direct replacement for 3FS-356 in existing designs?

A: Yes. The F56-045 meets all critical electrical parameters (115V primary, 28V/56V secondary, 90mA/45mA output, 2.4VA minimum power) and mechanical requirements (through-hole, PC pin termination, laminated core). The smaller physical dimensions of F56-045 (34.93mm L × 28.58mm W × 30.15mm H) provide additional layout margin and do not create compatibility issues.

Q: Are there any voltage or current derating considerations when substituting F56-045 for 3FS-356?

A: No. Both transformers are rated identically for primary voltage (115V), secondary voltages (28V parallel, 56V series), and output currents (90mA parallel, 45mA series). The F56-045 power rating of 2.5VA exceeds the 3FS-356 specification of 2.4VA, providing additional margin.

Q: Do both parts meet the same isolation and safety standards?

A: Yes. Both the 3FS-356 and F56-045 are rated at 2500Vrms isolation voltage and classified under ECCN EAR99 with HTSUS code 8504.31.4035. Both maintain RoHS compliance (3FS-356: RoHS Compliant; F56-045: ROHS3 Compliant).

Q: What is the difference in packaging between these parts?

A: The 3FS-356 is supplied in tube packaging, while the F56-045 is supplied in box packaging. Both are through-hole mounted components with PC pin termination suitable for standard PCB assembly processes.

Q: Can these transformers be used interchangeably in parallel or series secondary configurations?

A: Yes. Both transformers feature dual secondary windings that support identical parallel (28V, 90mA) and series (56V, 45mA) configurations. The winding configuration and center tap status (no center tap on either part) are identical.

Q: Are there any compliance or regulatory differences between 3FS-356 and F56-045?

A: Both parts are RoHS compliant and classified under the same ECCN and HTSUS codes. The F56-045 carries ROHS3 certification, which represents a more recent compliance standard than the 3FS-356 RoHS designation. Both are acceptable for equivalent applications.

Q: What is the moisture sensitivity level (MSL) difference, and does it affect substitution?

A: The 3FS-356 is rated MSL 1 (unlimited), while the F56-045 is listed as Not Applicable. Both ratings indicate minimal moisture sensitivity risk during storage and handling. This difference does not affect substitution eligibility.