L77DD50ST D-Sub 50 Position Receptacle Connector

Part Overview

The L77DD50ST is a 50 position D-Sub receptacle connector manufactured by Amphenol ICC (Commercial Products). This connector features female sockets with vertical solder termination and is designed for through-hole mounting applications. The part maintains active product status with 844 units currently in stock.

Substitute parts become necessary when the primary component experiences supply constraints, obsolescence, or when design requirements necessitate alternative electrical or mechanical specifications. The following equivalent and substitute parts provide functional alternatives based on matching core electrical and mechanical parameters.

Substiute Parts

L77DD50ST

Amphenol ICC (Commercial Products)In Stock: 917L77DD50ST Datasheet

Current PartRFQ

172-050-212R001

NorComp Inc.In Stock: 772172-050-212R001 Datasheet

SimilarRFQ

DDM50S332N

Amphenol ICC (FCI)In Stock: 871DDM50S332N Datasheet

SimilarRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitute parts for the L77DD50ST are identified based on matching the following critical parameters: 50 position count, D-Sub shell size 5 (DD, D), receptacle configuration with female sockets, solder termination, and through-hole mounting capability. All substitute parts listed maintain the same connector style and basic electrical characteristics.

The substitution logic prioritizes parts that maintain compatibility with the primary electrical specifications (300V voltage rating, 7.5A current rating) and operating temperature range (-55°C ~ 125°C). Mechanical compatibility is ensured through matching shell size, position count, and mounting methodology.

Parameter Comparison

Engineering Selection Recommendations

DDM50S332N (Amphenol ICC FCI): This part provides direct electrical equivalence to the L77DD50ST with matching 7.5A current rating and 300V voltage rating across the identical -55°C ~ 125°C operating temperature range. Both parts maintain UL94 V-0 flammability compliance and active product status. The primary distinction is the shell finish (yellow cadmium plated versus tin plated) and contact material (phosphor bronze versus brass). The DDM50S332N carries RoHS non-compliant status, which may restrict use in applications requiring RoHS compliance. This part is suitable for applications where RoHS compliance is not mandated.

172-050-212R001 (NorComp Inc.): This part shares the same 50 position, shell size 5, and solder termination characteristics. However, it operates at a reduced current rating of 5A compared to the 7.5A specification of the L77DD50ST. The operating temperature range is narrower (-50°C ~ 100°C versus -55°C ~ 125°C). The voltage rating is not specified in available documentation. This part carries obsolete product status and ROHS3 compliance. The 172-050-212R001 is suitable only for applications with reduced current and temperature requirements and where obsolete component sourcing is acceptable.

Frequently Asked Questions (FAQ)

Q: Can the DDM50S332N directly replace the L77DD50ST in all applications?

A: The DDM50S332N provides electrical equivalence in current rating (7.5A), voltage rating (300V), and operating temperature range (-55°C ~ 125°C). Both parts are active products with UL94 V-0 compliance. The primary consideration is RoHS compliance status: the L77DD50ST is RoHS compliant while the DDM50S332N is RoHS non-compliant. Applications requiring RoHS compliance must use the L77DD50ST or the 172-050-212R001.

Q: What are the limitations of the 172-050-212R001 as a substitute?

A: The 172-050-212R001 has a reduced current rating of 5A compared to the L77DD50ST specification of 7.5A. The operating temperature range is limited to -50°C ~ 100°C versus -55°C ~ 125°C. The part carries obsolete product status. These limitations restrict its use to applications with lower current demands and narrower temperature operating windows.

Q: Are there mechanical compatibility concerns between these substitute parts?

A: All three parts share identical shell size 5 (DD, D) specifications, 50 position count, and 3-row configuration. The L77DD50ST and DDM50S332N both feature through-hole mounting. The 172-050-212R001 supports both panel mount and through-hole mounting, providing additional flexibility. Mechanical compatibility is maintained across all three parts for standard through-hole PCB applications.

Q: What is the significance of shell finish differences between the L77DD50ST and DDM50S332N?

A: The L77DD50ST features tin-plated steel shell finish while the DDM50S332N uses yellow cadmium-plated steel. Both finishes provide corrosion protection and electrical conductivity. The choice between them depends on application environment and any specific material restrictions. Cadmium plating may be restricted in certain jurisdictions or applications due to environmental regulations.

Q: How do contact material differences affect connector performance?

A: The L77DD50ST uses brass contacts while the DDM50S332N uses phosphor bronze contacts. Both materials are suitable for signal-level applications with gold plating. Phosphor bronze offers slightly higher spring force and durability in high-cycle mating applications. Brass provides excellent electrical conductivity and corrosion resistance. For standard signal applications, both materials perform equivalently.

Q: Is the 172-050-212R001 suitable for new designs?

A: The 172-050-212R001 carries obsolete product status, indicating it is no longer in active production. While 754 units are currently in stock, this part should not be selected for new designs. It is suitable only for legacy system maintenance or repair applications where component compatibility with existing assemblies is required.