TE Connectivity 3-643821-8 Equivalent & Substitute Parts

Part Overview

The TE Connectivity 3-643821-8 is an 8-position rectangular receptacle connector from the MTA-156 series, designed for IDC (Insulation Displacement Contact) termination with 26 AWG discrete or ribbon cable. This connector features a closed end design with polarizing key, tin contact finish, and free-hanging in-line mounting configuration. The part is currently active in production with RoHS compliance and unlimited moisture sensitivity rating (MSL 1). Substitute parts are identified when inventory constraints, lead time requirements, or procurement preferences necessitate alternative sourcing while maintaining identical electrical and mechanical compatibility.

Key Parameters

Parameter	Value
Connector Type	Receptacle
Number of Positions	8
Pitch	0.156" (3.96mm)
Contact Type	Female Socket
Cable Termination Method	IDC
Wire Gauge	26 AWG
Contact Finish	Tin
Mounting Type	Free Hanging (In-Line)
Series	MTA-156
RoHS Status	RoHS Compliant

Substitute Part Grouping Explanation

Substitution eligibility for the TE Connectivity 3-643821-8 is determined by strict equivalence across the following critical parameters: connector type (receptacle), number of positions (8), pitch specification (0.156"), contact type (female socket), cable termination method (IDC), wire gauge compatibility (26 AWG), contact finish (tin), mounting configuration (free hanging in-line), and series designation (MTA-156). All substitute parts must maintain identical electrical performance characteristics and mechanical interface dimensions. Compliance certifications including RoHS status and moisture sensitivity level must be equivalent or superior. Parts that deviate in any of these core parameters are not considered direct substitutes and cannot be used interchangeably without design modification.

Parameter Comparison

Parameter	3-643821-8 (Main Part)	3-640430-8 (Substitute)	Compatibility
Manufacturer	TE Connectivity AMP Connectors	TE Connectivity AMP Connectors	Identical
Category	Rectangular Connectors	Rectangular Connectors	Identical
Series	MTA-156	MTA-156	Identical
Connector Type	Receptacle	Receptacle	Identical
Number of Positions	8	8	Identical
Pitch	0.156" (3.96mm)	0.156" (3.96mm)	Identical
Contact Type	Female Socket	Female Socket	Identical
Cable Termination	IDC	IDC	Identical
Wire Gauge	26 AWG	26 AWG	Identical
Wire Type	Discrete or Ribbon Cable	Discrete or Ribbon Cable	Identical
Mounting Type	Free Hanging (In-Line)	Free Hanging (In-Line)	Identical
Fastening Type	Locking Ramp	Locking Ramp	Identical
Contact Finish	Tin	Tin	Identical
Contact Finish Thickness	80.0µin (2.03µm)	80.0µin (2.03µm)	Identical
Color	Blue	Blue	Identical
RoHS Status	RoHS Compliant	RoHS Compliant	Identical
MSL Rating	1 (Unlimited)	1 (Unlimited)	Identical
Product Status	Active	Active	Identical
ECCN	EAR99	EAR99	Identical
HTSUS Code	8536.69.8000	8536.69.8000	Identical
Features	Closed End, Polarizing Key	Closed End	Main part includes polarizing key feature

Engineering Selection Recommendations

Both the 3-643821-8 and 3-640430-8 are active production parts manufactured by TE Connectivity with identical RoHS compliance and regulatory certifications. Selection between these parts is based on availability and procurement requirements rather than technical performance differences. The 3-643821-8 includes a polarizing key feature for additional keying security, while the 3-640430-8 provides the same electrical and mechanical interface without this feature. Both parts satisfy the MTA-156 series specification for 8-position IDC receptacle connectors with 26 AWG wire compatibility. Current inventory levels show 1459 units available for the 3-640430-8 substitute part compared to 840 units for the main part number, making the substitute a viable alternative for high-volume procurement scenarios.

Frequently Asked Questions (FAQ)

Question	Answer
Can the 3-640430-8 be used as a direct replacement for the 3-643821-8?	Yes, the 3-640430-8 is electrically and mechanically compatible with the 3-643821-8. Both connectors share identical pitch, contact configuration, termination method, and wire gauge specifications. The primary difference is the absence of the polarizing key feature on the substitute part.
What is the significance of the polarizing key feature on the main part?	The polarizing key on the 3-643821-8 provides mechanical keying to prevent incorrect mating orientation. The 3-640430-8 lacks this feature but maintains all other electrical and mechanical specifications.
Are both parts RoHS compliant?	Yes, both the 3-643821-8 and 3-640430-8 are RoHS compliant with identical MSL 1 (unlimited) moisture sensitivity ratings.
What wire gauges are compatible with these connectors?	Both connectors are specified for 26 AWG wire and support discrete or ribbon cable termination via IDC method.
Are there any differences in contact finish specifications?	No, both parts feature tin contact finish with identical 80.0µin (2.03µm) thickness specifications.
Can these connectors be used with ribbon cable?	Yes, both the 3-643821-8 and 3-640430-8 support ribbon cable termination through their IDC contact design.
What is the pitch specification for these connectors?	Both connectors feature 0.156" (3.96mm) pitch spacing, which is the standard for the MTA-156 series.
Are there inventory considerations for part selection?	The 3-640430-8 substitute part has higher current inventory (1459 units) compared to the main part (840 units), which may influence procurement decisions for large-volume applications.