SI-40143 Equivalent & Substitute Parts Reference

Part Overview

The SI-40143 is a 4-port RJ45 through-hole modular connector manufactured by Stewart Connector, designed for 10/100 Base-T Ethernet applications with AutoMDIX capability. This connector features a 90° right-angle orientation, solder termination, and integrated EMI shielding with board guide support. The product is currently active in production with 858 units in stock.

Substitute parts are identified when equivalent electrical and mechanical parameters align with the main part's specifications, enabling direct replacement in PCB designs without functional compromise.

Substiute Parts

SI-40143

Stewart ConnectorIn Stock: 948SI-40143 Datasheet

Current PartRFQ

7499031120A

Würth ElektronikIn Stock: 9657499031120A Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

The substitute part 7499031120A (Würth Elektronik WE-RJ45 LAN series) qualifies as an equivalent based on the following critical parameters:

• Connector Type & Port Configuration: Both parts are 4-port RJ45 connectors with identical electrical specifications for 10/100 Base-T and AutoMDIX functionality
• Mechanical Compatibility: Both feature through-hole mounting, 90° right-angle orientation, solder termination, and board guide support
• Electrical Performance: Both provide shielded construction with EMI finger protection and gold-plated contacts
• Environmental Ratings: Both maintain MSL 1 (Unlimited) moisture sensitivity classification and REACH Unaffected status
• Physical Dimensions: Height above board differs minimally (0.545" vs 0.531"), within acceptable tolerance for PCB layout compatibility

The substitute relationship is based strictly on functional equivalence in the modular connector category for Ethernet applications.

Parameter Comparison

Engineering Selection Recommendations

SI-40143 (Stewart Connector MagJack® ST SI-40000 Series)

• Product Status: Active
• RoHS Compliance: Non-compliant
• Suitable for applications where RoHS compliance is not required
• 858 units currently in stock

7499031120A (Würth Elektronik WE-RJ45 LAN Series)

• Product Status: Active
• RoHS Compliance: ROHS3 Compliant
• Recommended for new designs requiring RoHS3 compliance
• 909 units currently in stock
• Operating Temperature Range: -40°C ~ 85°C (specified)

Selection between these parts should be based on regulatory compliance requirements and operating temperature specifications for the target application.

Frequently Asked Questions (FAQ)

Q: Can 7499031120A directly replace SI-40143 in existing PCB designs? A: Yes. Both connectors share identical electrical specifications, port configuration, mounting type, and orientation. The 0.014" (0.35mm) height difference is within standard PCB layout tolerances for through-hole components.

Q: What is the primary difference between these two parts? A: The main difference is RoHS compliance status. SI-40143 is RoHS non-compliant, while 7499031120A is ROHS3 compliant. Additionally, 7499031120A specifies an operating temperature range of -40°C ~ 85°C, whereas SI-40143 does not provide this specification.

Q: Are the packaging formats compatible? A: SI-40143 packaging is not specified in the provided data. 7499031120A is supplied in Tube packaging. Verify packaging requirements for your procurement and assembly processes.

Q: Do both connectors support the same Ethernet standards? A: Yes. Both are rated for 10/100 Base-T applications with AutoMDIX functionality and identical shielding specifications (Shielded, EMI Finger).

Q: Which part should I specify for new product designs? A: For new designs, 7499031120A is recommended due to ROHS3 compliance and specified operating temperature range, ensuring alignment with current regulatory standards and environmental specifications.