SG27 Inrush Current Limiter - Equivalent & Substitute Parts

Part Overview

The SG27 is an active Inrush Current Limiter manufactured by Ametherm, part of the SURGE-GARD™ series. This component is designed to limit inrush current in electrical circuits, with a nominal resistance of 10 Ohms at ±15% tolerance and a maximum steady-state current rating of 6 A. The device is housed in a 0.500" (12.70mm) diameter package with 0.310" (7.87mm) lead spacing.

The SG27 maintains Active product status and carries ROHS3 compliance with CSA and UR approvals. Finding equivalent or substitute components may be necessary due to inventory constraints, lead time requirements, or application-specific packaging preferences while maintaining functional compatibility.

Substiute Parts

SG27

AmethermIn Stock: 931SG27 Datasheet

Current PartRFQ

B57364S0100M000

EPCOS - TDK ElectronicsIn Stock: 5034B57364S0100M000 Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for inrush current limiters is determined by the following critical parameters:

• Nominal Resistance Value: Both the main part and substitute must share the same 10 Ohm nominal resistance to maintain circuit design intent.
• Tolerance Range: The substitute tolerance must be compatible with circuit requirements. The SG27 specifies ±15%, while the B57364S0100M000 specifies ±20%.
• Steady-State Current Rating: The substitute must equal or exceed the application's maximum steady-state current requirement. The SG27 is rated for 6 A; the B57364S0100M000 is rated for 7.5 A.
• Regulatory Compliance: Both parts must maintain ROHS3 compliance and possess appropriate safety certifications (CSA, UR, UL, VDE, CQC).
• Package Compatibility: Physical dimensions (diameter and lead spacing) must accommodate the circuit board layout and mechanical constraints.

Parameter Comparison

Engineering Selection Recommendations

Both the SG27 and B57364S0100M000 meet the core functional requirements for 10 Ohm inrush current limiting applications. Selection between these parts should be based on the following factors:

SG27 Selection Criteria:

• Applications requiring the smaller 0.500" (12.70mm) package diameter for space-constrained designs.
• Circuits where the tighter ±15% tolerance is a design requirement.
• Systems requiring CSA and UR certifications specifically.

B57364S0100M000 Selection Criteria:

• Applications where the higher 7.5 A steady-state current rating provides additional design margin beyond the 6 A requirement.
• Designs accommodating the larger 0.827" (21.00mm) package diameter.
• Systems requiring UL, VDE, or CQC certifications.

Both parts maintain ROHS3 compliance and REACH Unaffected status, ensuring regulatory alignment for current manufacturing standards.

Frequently Asked Questions (FAQ)

Q: Can the B57364S0100M000 directly replace the SG27 in all applications?

A: Functional substitution is possible for circuits designed around 10 Ohm inrush current limiting with 6 A maximum steady-state current. However, the B57364S0100M000 has a larger package diameter (0.827" vs. 0.500"), which may require board layout modifications. Verify that the ±20% tolerance of the substitute is acceptable for your circuit design, as it is wider than the SG27's ±15% tolerance.

Q: What are the key differences between these two parts?

A: The primary differences are package size, tolerance specification, and current rating. The SG27 offers a compact 0.500" diameter package with ±15% tolerance and 6 A rating. The B57364S0100M000 provides a larger 0.827" diameter package with ±20% tolerance and a higher 7.5 A rating. Both maintain identical 10 Ohm nominal resistance and ROHS3 compliance.

Q: Are the lead spacings compatible?

A: Lead spacing is nearly identical: SG27 at 0.310" (7.87mm) and B57364S0100M000 at 0.295" (7.50mm). This minimal difference should not affect standard PCB footprint compatibility for most applications.

Q: Which certifications should I prioritize for my application?

A: Certification selection depends on your end-use market and regulatory requirements. The SG27 carries CSA and UR approvals, while the B57364S0100M000 carries CQC, UL, and VDE approvals. Verify which certifications are required by your application's safety and compliance standards.

Q: Does the higher current rating of the B57364S0100M000 affect circuit behavior?

A: The higher 7.5 A rating of the B57364S0100M000 does not negatively affect circuits designed for 6 A operation. The higher rating provides additional thermal and electrical margin. However, the operating resistance at current and thermal characteristics may differ; consult detailed datasheets for thermal performance comparisons if thermal management is critical to your design.