차폐형 대비 비차폐형 RJ45 커넥터: 차이점은 무엇인가요?

RJ45 connectors are a critical component in Ethernet networking, widely used to connect computers, routers, switches, and other devices. When choosing the right RJ45 connector (this article focuses on PCB-mount RJ45 connectors ) one key decision is whether to use shielded 또는 unshielded versions. This choice affects electromagnetic performance, mechanical design, and the connector’s suitability for various application environments..

What Are Shielded RJ45 Connectors?

Shielded RJ45 connectors incorporate a metal shield 또는 grounding shell around the plastic housing of the connector. This shield serves two primary purposes:

• Reduce Electromagnetic Interference (EMI) from external sources

• Contain Radiated Emissions from within the device

Shielded connectors are typically used with STP/FTP Ethernet cables and must be properly grounded through the PCB or chassis to be effective.

✅ Examples of Shielded RJ45 Jacks:

• LPJG47047A4NL – 2×4 Shielded RJ45 Magnetic Jacks Support PoE+

• LPJ16264A28NL – 8P8C RJ45 PCB Jack With Shield EMI Tabs

• LPJ16258AENL – 10/100 Base-T PoE RJ45 Connector with Integrated Magnetics

What Are Unshielded RJ45 Connectors?

Unshielded RJ45 connectors do not include any metal shield on the outer shell. They are fully enclosed in plastic, making them lighter, easier to install, and more cost-effective. These connectors are typically used with UTP cables in low-interference environments such as home routers, consumer electronics, or office equipment.

Despite lacking shielding, unshielded RJ45 connectors can still include integrated magnetics and LED indicators, enabling them to meet the electrical requirements of Ethernet standards like 10/100/1000Base-T.

✅ Examples of Unshielded RJ45 Jacks:

• LPJ0012NNL – 1×1 Port Unshielded RJ45 Jack Tab Down

• LPJE180NNL – RJ45 Modular Jack without Magnetics and LED

• LPJE101NNL – Compact unshielded 8P8C Jack Tab UP

Key Differences Between Shielded and Unshielded RJ45 Connectors

기능	Shielded RJ45 Connectors	Unshielded RJ45 Connectors
EMI/RFI Protection	✅ High	❌ Low
External Housing	Metal shielded	Full plastic
Signal Integrity in Harsh Environments	우수함	기본
비용	높음	낮음
일반적인 케이블 유형	STP / FTP	UTP
Grounding Required	있음	없음
사용 사례	Industrial, PoE switches, medical, telecom	Home gateways, printers, consumer electronics

How to Choose Between Shielded and Unshielded RJ45

When selecting an RJ45 connector for your PCB, consider the following:

✅ Choose 차폐형 RJ45 높은 서버 캐비닛을 사용하고 대칭적인 케이블 길이를 원할 때

• Device is used in EMI-sensitive environments (factories, data centers, power systems)

• You are designing for 이더넷을 통한 전력 공급(PoE) (PoE/PoE+)

• The product will be installed near high-frequency equipment

✅ Choose Unshielded RJ45 Modular Jack when:

• 비용 최적화가 우선 순위

• The environment is low in EMI/RFI

• Ease of assembly and simplified PCB layout is desired

적용 시나리오

산업 분야	Recommended Type	이유
산업 자동화	Shielded	Strong EMI resistance needed
소비자 전자제품	Unshielded	Lightweight, cost-effective
Telecom / PoE Switches	Shielded	Power and signal stability
Office Networking	Unshielded	Quiet EMI environment
의료 기기	Shielded	Signal integrity is critical

결론

두 기술 모두 shielded 및 unshielded RJ45 connectors have their roles in modern Ethernet networking. The decision depends on EMI environment, device application, cost constraints, and assembly design. When building reliable, standards-compliant Ethernet ports into your hardware, be sure to match the connector’s shielding level with your real-world application requirements.

Whether you’re designing a compact consumer device or an industrial-grade switch, the right RJ45 커넥터 is a critical choice for long-term performance and compliance.

🔎 Frequently Asked Questions (FAQ)

Q1: Can an unshielded RJ45 connector include magnetics and LEDs?

A: Yes. Unshielded RJ45 connectors can fully integrate magnetics (such as isolation transformers and common-mode chokes) and LED indicators. The absence of shielding only affects EMI performance, not functionality.

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Q2: Is shielding required for Ethernet compliance?

A: No. Ethernet standards like IEEE 802.3 do not mandate shielding. However, shielding is recommended in high-EMI environments to maintain signal integrity and reduce emissions.

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Q3: Will using a shielded RJ45 with unshielded cable cause problems?

A: It may reduce the effectiveness of the shield. For optimal EMI performance, the connector and cable should both be shielded and properly grounded.

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Q4: Do shielded RJ45 connectors require a PCB ground connection?

A: Yes. The metal shell of a shielded RJ45 must be electrically connected to the PCB ground plane or chassis to provide EMI protection. Without grounding, the shield is ineffective.

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Q5: What are the signs that I need a shielded RJ45 instead of unshielded?

A: Consider a shielded RJ45 if:

• Your product operates in environments with motors, RF transmitters, or power supplies

• You’ve experienced EMI-related performance issues

• Your device needs to meet stringent EMC (Electromagnetic Compatibility) regulations

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Q6: How do I identify if a connector is shielded or unshielded?

A: Visual inspection can help:

• Shielded RJ45s have a metal shell around the port, often silver in color, and may include grounding tabs.

• Unshielded RJ45s are typically all-plastic and do not have any metal shell.