SG190 Inrush Current Limiter - Equivalent & Substitute Parts

Part Overview

The SG190 is an active inrush current limiter manufactured by Ametherm under the SURGE-GARD™ series. This component is designed to limit inrush current in power supply circuits and related applications. The part operates at 5 Ohms resistance with a steady-state maximum current rating of 4 A and is housed in a 0.600" (15.24mm) diameter package. The SG190 maintains active product status with full ROHS3 compliance and CSA/UR approval certifications. Substitute parts are identified when equivalent electrical performance and mechanical compatibility can be maintained within specified tolerance ranges.

Substiute Parts

SG190

AmethermIn Stock: 1618SG190 Datasheet

Current PartRFQ

B57213P0509M301

EPCOS - TDK ElectronicsIn Stock: 10312B57213P0509M301 Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the SG190 is determined by the following critical parameters:

• Resistance value at 25°C: 5 Ohms (primary electrical specification)
• Tolerance range: ±15% to ±20% (acceptable variance for inrush current limiting applications)
• Steady-state current rating: minimum 4 A (must meet or exceed the original specification)
• Resistance at operating current: comparable performance (106-150 mOhms range)
• Package diameter: 0.600" (15.24mm) to 0.571" (14.50mm) (mechanical compatibility within standard tolerances)
• Lead spacing: 0.310" (7.87mm) to 0.295" (7.50mm) (PCB footprint compatibility)
• RoHS compliance: ROHS3 Compliant (regulatory requirement)

The B57213P0509M301 meets these substitution criteria with equivalent 5 Ohm resistance, higher current rating (6 A), and compatible mechanical dimensions.

Parameter Comparison

Engineering Selection Recommendations

The B57213P0509M301 (EPCOS - TDK Electronics, P13 series) is a qualified substitute for the SG190 based on the following engineering criteria:

• Both parts maintain identical 5 Ohm resistance specifications at 25°C, ensuring equivalent inrush current limiting performance in the primary operating range.
• The B57213P0509M301 provides a higher steady-state current rating (6 A versus 4 A), offering improved thermal margin and operational headroom.
• Mechanical dimensions are compatible within standard PCB assembly tolerances, with the substitute part fitting existing footprints designed for the SG190.
• Both components maintain ROHS3 compliance and REACH unaffected status, satisfying current regulatory requirements.
• The substitute part carries ROHS3 certification and maintains equivalent export classification (EAR99).

Selection between these parts should be based on availability, lead time, and cost considerations, as both meet the specified electrical and mechanical requirements for inrush current limiting applications.

Frequently Asked Questions (FAQ)

Q: Can the B57213P0509M301 be used as a direct replacement for the SG190?

A: Yes. Both parts share identical 5 Ohm resistance values and compatible mechanical dimensions. The substitute part meets or exceeds all critical electrical parameters specified for the SG190.

Q: What is the tolerance difference between these parts?

A: The SG190 carries ±15% tolerance, while the B57213P0509M301 carries ±20% tolerance. Both tolerances are acceptable for inrush current limiting applications where the primary function is to limit transient current spikes rather than maintain precise resistance values.

Q: Does the higher current rating of the B57213P0509M301 affect compatibility?

A: No. A higher current rating indicates improved thermal performance and operational margin. The substitute part will operate safely in circuits designed for the 4 A SG190 specification.

Q: Are there mechanical fit concerns with the slightly smaller diameter?

A: No. The diameter difference (0.600" to 0.571") and lead spacing difference (0.310" to 0.295") fall within standard PCB assembly tolerances and do not affect mechanical fit or electrical performance.

Q: Do both parts meet the same regulatory requirements?

A: Yes. Both the SG190 and B57213P0509M301 are ROHS3 compliant, REACH unaffected, and classified as EAR99 for export purposes.

Q: What is the resistance value at operating current for each part?

A: The SG190 exhibits 150 mOhms at operating current, while the B57213P0509M301 exhibits 106 mOhms. The lower resistance in the substitute part indicates improved thermal performance during steady-state operation.