TE Connectivity 643818-4 Rectangular Connector Equivalent & Substitute Parts

Part Overview

The TE Connectivity 643818-4 is a 4-position rectangular receptacle connector from the MTA-156 series, designed for IDC (Insulation Displacement Contact) termination with 20 AWG discrete or ribbon cable. This connector features a tin-lead contact finish, closed-end design with polarizing key, and free-hanging in-line mounting configuration. The part is currently active in production with 674 pieces in stock inventory.

Substitute parts are identified when equivalent electrical and mechanical specifications are maintained across connector position count, pitch, termination method, wire gauge, mounting type, and fastening mechanism. Alternative part numbers may offer improved compliance status, different packaging configurations, or enhanced inventory availability while preserving functional compatibility.

Substiute Parts

643818-4

TE Connectivity AMP ConnectorsIn Stock: 694643818-4 Datasheet

Current PartRFQ

3-643818-4

TE Connectivity AMP ConnectorsIn Stock: 81053-643818-4 Datasheet

DirectRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the TE Connectivity 643818-4 is determined by strict equivalence across the following critical parameters:

Electrical Compatibility Parameters:

• Number of positions: 4
• Pitch: 0.156" (3.96mm)
• Contact type: Female socket
• Wire gauge: 20 AWG
• Contact finish thickness: 80.0µin (2.03µm)

Mechanical Compatibility Parameters:

• Connector type: Rectangular receptacle
• Cable termination: IDC
• Wire type: Discrete or ribbon cable
• Mounting type: Free hanging (in-line)
• Fastening type: Locking ramp
• Number of rows: 1
• Features: Closed end, polarizing key

Environmental & Compliance Parameters:

• Moisture sensitivity level: 1 (unlimited)
• Series: MTA-156

The substitute part 3-643818-4 maintains identical electrical and mechanical specifications while differing in contact finish composition (tin versus tin-lead) and RoHS compliance status. Both parts share the same base product number (643818) and are manufactured by TE Connectivity AMP Connectors.

Parameter Comparison

Engineering Selection Recommendations

643818-4 (Tin-Lead Contact Finish): This part is suitable for applications where tin-lead contact finish is specified or required by design documentation. The part is active in production and maintains unlimited moisture sensitivity rating. However, this part carries RoHS non-compliant status, which may restrict use in regulated markets or applications subject to RoHS3 requirements.

3-643818-4 (Tin Contact Finish): This substitute part is functionally equivalent across all electrical and mechanical parameters while offering ROHS3 compliance. The tin contact finish maintains the same 80.0µin thickness specification as the main part. This part is recommended for applications requiring RoHS3 compliance or for new designs where lead-free contact finish is mandated. Significantly higher inventory availability (8026 pieces) supports supply chain continuity. Bulk packaging configuration is specified for this variant.

Both parts share identical connector specifications, series designation, and environmental ratings. Selection between these parts depends on compliance requirements and contact finish material specifications for the target application.

Frequently Asked Questions (FAQ)

Q: Are the 643818-4 and 3-643818-4 electrically interchangeable?

A: Yes. Both parts maintain identical electrical specifications including 4-position configuration, 0.156" pitch, 20 AWG wire gauge, female socket contact type, and IDC termination method. Electrical performance and signal integrity characteristics are equivalent.

Q: What is the difference between tin-lead and tin contact finishes in these connectors?

A: The 643818-4 features a tin-lead contact finish, while the 3-643818-4 features a tin contact finish. Both maintain the same 80.0µin (2.03µm) thickness specification. The primary difference is material composition, with tin-lead containing lead and tin containing only tin. This distinction affects RoHS compliance status.

Q: Why does the 3-643818-4 show higher inventory availability?

A: The 3-643818-4 is packaged in bulk configuration and carries ROHS3 compliance status, which typically results in higher production volumes and inventory levels compared to the non-compliant variant. The 8026-piece inventory for 3-643818-4 versus 674 pieces for 643818-4 reflects this market demand difference.

Q: Can I use the 3-643818-4 as a direct replacement for the 643818-4 in existing designs?

A: Mechanical and electrical compatibility is confirmed across all specified parameters. However, design documentation should be reviewed to confirm whether tin-lead contact finish is explicitly required. If the design specifies tin-lead material, substitution to tin finish requires design change documentation. If contact finish material is not specified, substitution is permissible.

Q: What does RoHS3 compliance mean for these connectors?

A: ROHS3 compliance indicates the part meets Restriction of Hazardous Substances Directive requirements, specifically restricting lead content. The 3-643818-4 meets these requirements; the 643818-4 does not. RoHS3 compliance is mandatory for many regulated markets and applications.

Q: Are the mounting and fastening characteristics identical between these parts?

A: Yes. Both parts feature free-hanging in-line mounting type and locking ramp fastening mechanism. Mechanical installation procedures and mounting compatibility are identical.

Q: What is the significance of the MTA-156 series designation?

A: MTA-156 is the connector series designation from TE Connectivity. Both the main part and substitute part belong to this series, confirming they share the same connector family specifications, including the 0.156" pitch standard and IDC termination compatibility.