TE Connectivity 643818-3 Rectangular Connector Equivalent & Substitute Parts

Part Overview

The TE Connectivity 643818-3 is a 3-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 957 pieces in stock inventory.

Substitute parts are identified to address specific application requirements including RoHS compliance status, packaging preferences, and contact finish specifications while maintaining full electrical and mechanical compatibility.

Substiute Parts

643818-3

TE Connectivity AMP ConnectorsIn Stock: 1019643818-3 Datasheet

Current PartRFQ

3-643818-3

TE Connectivity AMP ConnectorsIn Stock: 16833-643818-3 Datasheet

DirectRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution between TE Connectivity 643818-3 and equivalent parts is determined by strict adherence to the following critical parameters:

Critical Electrical and Mechanical Parameters:

• Connector type (Receptacle)
• Number of positions (3)
• Pitch spacing (0.156" / 3.96mm)
• Contact type (Female Socket)
• IDC cable termination method
• Wire gauge compatibility (20 AWG)
• Series designation (MTA-156)
• Mounting configuration (Free Hanging In-Line)
• Fastening mechanism (Locking Ramp)
• Polarizing key and closed-end design

Non-Critical Parameters Allowing Substitution:

• Contact finish material (Tin-Lead versus Tin) — both finishes provide equivalent electrical performance and mechanical interface
• Packaging format (Bulk versus standard) — does not affect connector functionality
• RoHS compliance status — determined by application regulatory requirements, not connector performance

Parts meeting all critical parameters are electrically and mechanically interchangeable regardless of contact finish or packaging variation.

Parameter Comparison

Engineering Selection Recommendations

Selection Criteria Based on Compliance and Product Status:

Both the 643818-3 and 3-643818-3 are active production parts from TE Connectivity AMP Connectors with identical electrical and mechanical specifications. Selection between these parts is determined by regulatory and procurement requirements:

Choose 643818-3 when:

• RoHS non-compliant applications are acceptable
• Tin-lead contact finish is specified or preferred
• Standard packaging format is required
• Existing inventory of 957 pieces meets project timeline

Choose 3-643818-3 when:

• RoHS compliance is mandated by application or regional regulations
• Tin contact finish meets application requirements
• Bulk packaging format is preferred for high-volume procurement
• Higher inventory availability (1667 pieces) supports extended production runs

Both parts share identical ECCN (EAR99), HTSUS (8536.69.8000), and MSL (1 - Unlimited) classifications. Contact finish material difference (Tin-Lead versus Tin) does not affect electrical performance or mechanical interface compatibility. Both connectors support identical IDC termination with 20 AWG discrete or ribbon cable.

Frequently Asked Questions (FAQ)

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

A: Yes. Both connectors are electrically identical. They feature the same 3-position receptacle configuration, 0.156" pitch, female socket contacts, IDC termination method, and 20 AWG wire gauge specification. Contact finish material (Tin-Lead versus Tin) does not affect electrical performance.

Q: What is the difference between Tin-Lead and Tin contact finishes?

A: The 643818-3 features Tin-Lead contact finish while the 3-643818-3 features Tin contact finish. Both finishes provide equivalent electrical conductivity and mechanical interface performance. The contact finish thickness is identical at 80.0µin (2.03µm) for both parts. Selection between finishes is determined by application regulatory requirements or design specifications.

Q: Why does the RoHS status differ between these parts?

A: The 643818-3 is RoHS non-compliant while the 3-643818-3 is RoHS compliant. This difference reflects the contact finish material composition. RoHS compliance is application-dependent and must be verified against project regulatory requirements. Both parts are functionally equivalent.

Q: Can I use these connectors with different wire gauges?

A: No. Both connectors are specified for 20 AWG wire only. IDC termination requires precise wire gauge matching for proper contact displacement and electrical connection. Using wire gauges outside the 20 AWG specification will result in improper termination and connection failure.

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

A: MTA-156 is the TE Connectivity series designation for rectangular connectors with 0.156" (3.96mm) pitch spacing. This series designation ensures mechanical and electrical compatibility across all parts within the series. Both substitute parts belong to the MTA-156 series and are fully compatible.

Q: Does packaging format affect connector performance?

A: No. The 643818-3 is supplied in standard packaging while the 3-643818-3 is supplied in bulk packaging. Packaging format is a procurement consideration only and does not affect connector electrical performance, mechanical interface, or reliability.

Q: Are these connectors suitable for ribbon cable applications?

A: Yes. Both connectors support discrete or ribbon cable termination via IDC method. The 20 AWG specification applies to both cable types. Ribbon cable must be properly aligned with the polarizing key during IDC termination.

Q: What does the polarizing key feature prevent?

A: The polarizing key is a mechanical feature that prevents incorrect connector orientation during mating. This ensures proper pin alignment and prevents reversed polarity connections that could damage connected circuitry.

Q: Can I substitute these connectors in existing designs without redesign?

A: Yes, provided the application regulatory requirements (RoHS compliance) and contact finish specifications are compatible with the substitute part. All critical electrical and mechanical parameters are identical, enabling direct substitution without circuit redesign or PCB modification.