SMB Connector Jack 131-3701-821 Equivalent & Substitute Parts

Part Overview

The Cinch Connectivity Solutions 131-3701-821 is an SMB connector jack with male pin configuration, designed for 50 ohm board edge end launch applications. This coaxial RF connector operates at frequencies up to 4 GHz and is rated for 335 V with an operating temperature range of -65°C to 165°C. The part is currently active in production and RoHS compliant. Equivalent and substitute parts are identified to support procurement flexibility, inventory management, and supply chain continuity for applications requiring identical electrical and mechanical specifications.

Substiute Parts

131-3701-821

Cinch Connectivity SolutionsIn Stock: 753131-3701-821 Datasheet

Current PartRFQ

131-3701-801

Cinch Connectivity SolutionsIn Stock: 2754131-3701-801 Datasheet

Parametric EquivalentRFQ

131-3701-811

Cinch Connectivity SolutionsIn Stock: 1224131-3701-811 Datasheet

Parametric EquivalentRFQ

903-518J-51P

Amphenol RFIn Stock: 13010903-518J-51P Datasheet

Parametric EquivalentRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the 131-3701-821 is determined by strict equivalence across the following critical parameters: connector style (SMB), connector type (jack with male pin), impedance (50 ohms), mounting configuration (board edge end launch), contact and shield termination method (solder), frequency rating (4 GHz maximum), fastening mechanism (snap-on), operating temperature range (-65°C to 165°C), voltage rating (335 V), mating cycle rating (500), material composition (brass body and center contact with PTFE dielectric), and moisture sensitivity classification (MSL 1).

All identified substitute parts meet these core electrical and mechanical requirements. Variations in regulatory compliance status (RoHS generation and REACH classification) and inventory availability do not affect functional interchangeability within the specified parameter set.

Parameter Comparison

Engineering Selection Recommendations

All four parts—131-3701-821, 131-3701-801, 131-3701-811, and 903-518J-51P—are functionally equivalent for applications requiring SMB jack connectors with 50 ohm impedance, board edge end launch mounting, and solder termination. Selection between these parts may be based on the following factors:

Cinch 131-3701-821: Original specification part with RoHS compliance status and established supply chain presence.

Cinch 131-3701-801: Identical electrical and mechanical specifications to 131-3701-821 with higher inventory availability (2648 units).

Cinch 131-3701-811: Meets ROHS3 compliance requirements with REACH affected status, suitable for applications with enhanced regulatory requirements.

Amphenol RF 903-518J-51P: Cross-manufacturer equivalent from Amphenol RF with ROHS3 compliance, REACH affected status, and highest inventory availability (12900 units). Insertion loss is specified at 0.3 dB.

All parts maintain active production status and are suitable for direct substitution within the specified parameter constraints.

Frequently Asked Questions (FAQ)

Q: Can 131-3701-801 be used as a direct replacement for 131-3701-821?

A: Yes. Both parts share identical electrical specifications (50 ohm impedance, 4 GHz frequency rating, 335 V voltage rating), mechanical configuration (SMB jack, male pin, board edge end launch, solder termination), and material composition (brass body and center contact with PTFE dielectric). The parts are functionally interchangeable.

Q: What is the difference between RoHS and ROHS3 compliance?

A: RoHS Compliant indicates compliance with the original Restriction of Hazardous Substances directive. ROHS3 Compliant indicates compliance with the updated RoHS 3 directive (2015/863/EU), which includes additional restricted substances. Both designations confirm hazardous substance restrictions; ROHS3 represents the current regulatory standard.

Q: Is the Amphenol RF 903-518J-51P compatible with designs specified for the Cinch 131-3701-821?

A: Yes. The 903-518J-51P meets all critical electrical and mechanical parameters: 50 ohm impedance, SMB jack configuration with male pin, board edge end launch mounting, solder termination, 4 GHz frequency rating, 335 V voltage rating, and identical material specifications. Cross-manufacturer substitution is supported within these parameter constraints.

Q: Does insertion loss affect substitution eligibility?

A: Insertion loss is specified only for the Amphenol RF 903-518J-51P (0.3 dB). This parameter does not disqualify substitution; it provides additional performance data for applications where insertion loss is a design consideration. The absence of insertion loss specification for other parts does not indicate incompatibility.

Q: Are there packaging or MSL considerations for these parts?

A: All parts are supplied in bulk packaging with MSL 1 (Unlimited) classification, indicating no moisture sensitivity constraints during storage or handling. Packaging and moisture sensitivity are equivalent across all four parts.

Q: Can these parts be used interchangeably in existing PCB designs?

A: Yes. All parts share identical mounting configuration (board edge, end launch, solder termination) and physical specifications. PCB footprints and assembly processes remain unchanged across all four parts.