L77DC37SA D-Sub 37 Position Receptacle Connector

Part Overview

The L77DC37SA is a 37-position D-Sub receptacle connector with female sockets, manufactured by Amphenol ICC. This right-angle solder-terminated connector is designed for through-hole mounting applications requiring 300V and 7.5A electrical performance. The product is currently active in status.

Component substitution becomes necessary when the primary supplier has extended lead times, when design compatibility with alternative manufacturers is required, or when specific compliance and environmental specifications must be matched. The substitute parts listed below share the core D-Sub 37-position receptacle configuration but differ in specific electrical ratings, mounting characteristics, and manufacturing compliance profiles.

Substiute Parts

L77DC37SA

Amphenol ICC (Commercial Products)In Stock: 858L77DC37SA Datasheet

Current PartRFQ

173-E37-211R001

NorComp Inc.In Stock: 971173-E37-211R001 Datasheet

SimilarRFQ

173-E37-211R141

NorComp Inc.In Stock: 1384173-E37-211R141 Datasheet

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174-E37-211R141

NorComp Inc.In Stock: 953174-E37-211R141 Datasheet

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174-E37-211R241

NorComp Inc.In Stock: 993174-E37-211R241 Datasheet

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Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for D-Sub 37-position receptacle connectors is determined by alignment of the following critical parameters:

Mandatory Matching Parameters:

• Connector type (D-Sub Receptacle, Female Sockets)
• Number of positions (37)
• Number of rows (2)
• Shell size and layout (4 / DC, C)
• Mounting type (Right Angle)
• Termination method (Solder)

Parameters Allowing Variation:

• Shell material finish (tin plated vs. yellow chromate plated)
• Contact finish thickness (exact thickness specifications may differ)
• Flange feature configuration (unthreaded housing vs. screwlock vs. standard screws)
• Current rating (7.5A primary specification vs. 5A substitute specifications)
• Voltage rating (300V primary vs. unspecified in substitutes)
• Operating temperature range (-55°C ~ 125°C primary vs. -50°C ~ 100°C substitutes)
• Dielectric material composition (thermoplastic glass-filled vs. polyamide nylon)
• RoHS and compliance status (RoHS compliant primary vs. RoHS non-compliant substitutes)
• Backset spacing (0.319" vs. 0.283" or 0.370")

All four substitute parts meet the core D-Sub 37-position receptacle functional requirements but operate under different electrical and environmental constraints than the primary L77DC37SA specification.

Parameter Comparison

Engineering Selection Recommendations

Primary Component (L77DC37SA): The Amphenol ICC L77DC37SA is the preferred selection for new designs. It meets current RoHS compliance requirements and supports the higher current rating (7.5A) and extended operating temperature range (-55°C ~ 125°C) with documented 300V voltage specification.

Substitute Selection Criteria:

173-E37-211R001: This NorComp part is the only substitute without mating-side screwlock or screw features, offering the closest mechanical profile to the primary L77DC37SA. However, it operates at reduced current (5A), narrower temperature range (-50°C ~ 100°C), and is obsolete with RoHS non-compliant status. Selection is appropriate only when backset spacing tolerance of 0.283" (7.20mm) is compatible with the design.

173-E37-211R141: This NorComp part adds female screwlock (4-40) fastening on the mating side. It maintains the 0.283" (7.20mm) backset spacing and operates under identical electrical and temperature constraints as the 173-E37-211R001. Selection is appropriate when mating-side female screwlock fastening is required and the smaller backset spacing accommodates the application.

174-E37-211R141: This NorComp part increases backset spacing to 0.370" (9.40mm) with female screwlock (4-40) fastening and includes specified brass contact material. It is suitable for applications where the larger backset spacing is required and mating-side female screwlock fastening is necessary. Product status is obsolete with RoHS non-compliance.

174-E37-211R241: This NorComp part maintains the 0.370" (9.40mm) backset spacing and incorporates standard 4-40 screws instead of female screwlock fastening on the mating side. Selection is appropriate when panel mounting with standard screw fastening is required and the larger backset spacing is compatible. Product is obsolete and RoHS non-compliant.

Compliance Consideration: All substitute parts are obsolete and RoHS non-compliant. Selection of any substitute requires design review to confirm compatibility with system-level regulatory requirements and environmental certifications.

Frequently Asked Questions (FAQ)

Q: Can the NorComp substitutes directly replace the Amphenol L77DC37SA?

A: Mechanical and electrical substitution depends on specific design constraints. All substitutes share the D-Sub 37-position receptacle configuration and UL94 V-0 flammability rating. However, the NorComp parts operate at 5A versus the L77DC37SA's 7.5A current rating and narrower operating temperature range (-50°C ~ 100°C versus -55°C ~ 125°C). Designs must confirm that the reduced current and temperature specifications do not exceed application requirements. Backset spacing differences (0.283" or 0.370" versus the original 0.319") must be verified against PCB mounting patterns.

Q: What is the significance of the backset spacing differences?

A: Backset spacing is the distance from the connector seating plane to the rear mounting surface. The L77DC37SA specifies 0.319" (8.10mm), while substitutes use either 0.283" (173-E37 series) or 0.370" (174-E37 series). This parameter directly affects PCB layout compatibility and panel cutout dimensions. Substitutes with different backset spacing require design verification to ensure physical fit without PCB routing conflicts or mounting surface interference.

Q: Why are all substitute parts listed as obsolete?

A: All NorComp substitute parts (173-E37 and 174-E37 series) carry obsolete product status. This indicates that these components are no longer manufactured or supported by the supplier. Selection of obsolete parts should be limited to legacy equipment repairs or long-term installed base support where design freeze constraints prevent migration to active alternatives.

Q: What does RoHS non-compliant status mean for the substitute parts?

A: The substitute parts are RoHS non-compliant, indicating they do not meet the Restriction of Hazardous Substances directive requirements. The primary L77DC37SA is RoHS compliant. Substitution of non-compliant parts in designs intended for markets with RoHS regulatory requirements is not permitted without design waiver approval and regulatory documentation. RoHS compliance is a system-level requirement that extends beyond individual component selection.

Q: How do the dielectric materials differ between the primary and substitute parts?

A: The L77DC37SA uses thermoplastic resin with glass filler, while all NorComp substitutes use polyamide (PA6T) nylon 6T. Both materials meet UL94 V-0 flammability standards. The material differences affect mechanical properties, moisture absorption, and long-term dimensional stability in high-humidity or elevated-temperature environments. Design environments requiring specific dielectric performance characteristics should be evaluated independently.

Q: What is the difference between the 173-E37 and 174-E37 series substitutes?

A: The primary difference is backset spacing. The 173-E37 series uses 0.283" (7.20mm) spacing, while the 174-E37 series uses 0.370" (9.40mm) spacing. Within each series, variations exist in flange features: unthreaded housing (173-E37-211R001), female screwlock (173-E37-211R141 and 174-E37-211R141), or standard screws (174-E37-211R241). Selection between series depends on PCB layout compatibility with the required backset spacing.

Q: Are the contact finish specifications compatible?

A: The L77DC37SA specifies gold plating at 8.00µin (0.203µm) thickness. All NorComp substitutes specify gold plating with flash thickness, which is significantly thinner and less specified than the primary part. Flash plating provides basic contact protection but offers reduced durability compared to the thicker 8.00µin specification. Applications requiring long connector life with frequent mating cycles should account for this difference in contact wear characteristics.