SG338 Inrush Current Limiter - Equivalent & Substitute Parts

Part Overview

The SG338 is an inrush current limiter manufactured by Ametherm, part of the SURGE-GARD™ series. This component is designed to limit inrush current in power supply circuits and related applications. The device operates at 10 Ohms resistance with a steady-state maximum current rating of 5 A and is housed in a 0.450" (11.43mm) diameter package. The product maintains Active status and is ROHS3 compliant with CSA and UR approvals. Substitute parts are identified when equivalent electrical performance can be maintained within the allowed parameter tolerances for this component category.

Substiute Parts

SG338

AmethermIn Stock: 735SG338 Datasheet

Current PartRFQ

B57238S0100M000

EPCOS - TDK ElectronicsIn Stock: 5557B57238S0100M000 Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

The B57238S0100M000 (EPCOS - TDK Electronics) qualifies as a substitute based on the following electrical and mechanical parameters:

Matching Criteria:

• Resistance value: 10 Ohms (identical)
• Steady-state current rating: 5 A (identical)
• Tolerance: ±20% (within acceptable substitution range for inrush current limiters; exceeds SG338 tolerance of ±15%)
• RoHS3 compliance: Confirmed
• REACH unaffected status: Confirmed
• Functional category: Inrush current limiter

Dimensional Consideration: The B57238S0100M000 has a larger diameter (0.630" / 16.00mm) and different lead spacing (0.295" / 7.50mm) compared to the SG338. Physical fit in the application circuit must be verified before substitution.

Parameter Comparison

Engineering Selection Recommendations

Both the SG338 and B57238S0100M000 maintain Active product status and ROHS3 compliance. The electrical specifications (10 Ohms, 5 A steady-state) are identical. Selection between these parts depends on:

1. Physical space constraints: The SG338 offers a smaller diameter (11.43mm vs. 16.00mm), making it suitable for compact layouts. The B57238S0100M000 requires additional board space.

2. Tolerance requirements: The SG338 provides tighter tolerance (±15%) compared to the B57238S0100M000 (±20%). Applications requiring stricter resistance accuracy should prioritize the SG338.

3. Regulatory compliance: Both parts satisfy ROHS3 and REACH requirements. The SG338 carries CSA and UR approvals, while the B57238S0100M000 carries UL approval. Verify which certification is required for your application.

4. Availability: The B57238S0100M000 has higher inventory availability (5462 pcs vs. 683 pcs for SG338).

Frequently Asked Questions (FAQ)

Q: Can the B57238S0100M000 directly replace the SG338 in my circuit?

A: Electrical substitution is valid based on matching 10 Ohm resistance and 5 A current rating. However, the larger physical dimensions (0.630" diameter vs. 0.450") and different lead spacing (0.295" vs. 0.350") require verification of mechanical fit on your PCB or assembly.

Q: Why does the B57238S0100M000 have a wider tolerance (±20% vs. ±15%)?

A: Tolerance specifications vary by manufacturer design and manufacturing process. For applications where resistance accuracy is critical, the SG338 with ±15% tolerance is the preferred choice.

Q: Are there any compliance differences between these parts?

A: Both parts are ROHS3 compliant and REACH unaffected. The SG338 carries CSA and UR approvals, while the B57238S0100M000 carries UL approval. Confirm which certification standard applies to your end application.

Q: What is the impact of the different lead spacing on substitution?

A: Lead spacing affects PCB hole positioning and mechanical assembly. The SG338 has 0.350" spacing while the B57238S0100M000 has 0.295" spacing. Verify that your PCB layout accommodates the substitute part's lead configuration before implementation.

Q: Which part should I select for new designs?

A: For new designs, either part is acceptable based on electrical equivalence. Consider the SG338 if compact size and tighter tolerance are priorities, or the B57238S0100M000 if higher inventory availability is advantageous. Confirm physical fit and required certifications for your specific application.