【Circuit Standard Design】 Standard Circuit Design Reference for 10 Gigabit Ethernet Lightning Protection & Static Electricity Protection Solutions

This solution is a standard 10GbE circuit solution from VOOHU Electronics Technology Co., Ltd. The company has focused on the field of communication electronic components for over 8 years, adhering to the business strategy and service philosophy of "Choose VOOHU, truly reliable," providing comprehensive technical solution support.

10G BASE-T Lightning and Static Electricity Protection & Current-Type PHY

Solution Overview

1. Primary Side Wiring:

• Differential Pair Connection: The primary side of the network transformer is connected to differential pairs TD0/TD1 and RD0/RD1 respectively. The wiring sequence of the four differential pairs can be interchanged during PCB routing.
• Decoupling Capacitor: The primary side should be connected to GND through a 100nF capacitor to ensure signal stability and integrity.
• VCC Power Supply: For current-type PHYs, the primary coil needs to be connected to the PHY's VCC to filter out high-frequency noise and ensure signal stability.

2. Secondary Side Wiring:

• RJ45 Connection: The two sets of differential transmit/receive signals on the secondary side should be connected to pins 1, 2, 3, 6 and 4, 5, 7, 8 of the RJ45 interface, respectively.
• BOB Smith Circuit: A 75Ω resistor should be connected to the secondary side, followed by a 1nF capacitor with a withstand voltage of 2KV or higher, connected to the chassis ground. 1206-package surface-mount ceramic capacitors or high-voltage ceramic capacitors with wide lead pitch are recommended.

3. Grounding Treatment:

• Floating Pins: The floating pins of the RJ45 interface should also be connected to the chassis ground using a similar design, ultimately flowing into the earth to ensure the integrity of the entire circuit's grounding system.

Circuit Function Description:

• BOB Smith Circuit: This circuit, consisting of a 75Ω resistor and a 1nF capacitor, provides a return path for common-mode signals, effectively filtering out common-mode signals, improving electromagnetic interference (EMI), and suppressing inrush current to some extent.
• Decoupling Capacitor: A 100nF capacitor is used to filter high-frequency noise, ensuring signal stability and integrity.
• Voltage Rating Capacitor: The 1nF capacitor must have a voltage rating of 2KV or higher to ensure reliability under high-voltage conditions.

10G BASE-T Lightning and Static Electricity Protection & Voltage-Type PHY

Solution Overview

1. Primary Side Wiring:

• Differential Pair Connection: The primary side of the network transformer is connected to the differential pairs TD0/TD1 and RD0/RD1 respectively. The pin order of the four differential pairs can be interchanged during PCB routing.
• Decoupling Capacitor: The primary side should be connected to GND through a 100nF capacitor to ensure signal stability and integrity.

2. Secondary Side Wiring:

• RJ45 Connection: The two sets of transmit and receive differential signals on the secondary side should be connected to pins 1, 2, 3, 6 and 4, 5, 7, 8 of the RJ45 interface respectively.
• BOB Smith Circuit: A 75Ω resistor should be connected to the secondary side, followed by a 1nF capacitor with a voltage rating of 2KV or higher, connected to the chassis ground. A 1206-package surface-mount ceramic capacitor or a high-voltage ceramic capacitor with a wide lead pitch is recommended.

3. Grounding Treatment:

• Floating Pins: The floating pins of the RJ45 interface should also be connected to the chassis ground using a similar design, ultimately flowing into the earth to ensure the integrity of the entire circuit's grounding system.

Circuit Function Description

• BOB Smith Circuit: This circuit, consisting of a 75Ω resistor and a 1nF capacitor, provides a return path for common-mode signals, effectively filtering out common-mode signals, improving electromagnetic interference (EMI), and suppressing inrush current to some extent.
• Decoupling Capacitor: A 100nF capacitor is used to filter out high-frequency noise, ensuring signal stability and integrity.
• Voltage Rating Capacitor: The 1nF capacitor must have a voltage rating of 2KV or higher to ensure reliability under high-voltage environments.

Advantages of this solution:

For outdoor 10000M network port surge protection, this solution employs two-stage protection, ensuring reliable operation, guaranteeing signal integrity at high temperatures, and meeting IEC61000-4-2, Class 4, contact discharge 30kV, air discharge 30kV. (IEC61000-4-5 10/700μs, 40Ω, 6kV, ±5 times)

Product Illustration -- Related Product Recommendations

Tel: 400-1048-018; E-mail: wohu@wohu-tek.com;

From its establishment in 2018 to its overseas expansion in 2025, Voohu Electronics has become a reliable partner for over 1,500 companies thanks to its "superior quality, reasonable prices, attentive service, and reliable delivery."

If you are also looking for a "worry-free, cost-effective, and convenient" supplier of communication electronic components, consider Voohu. After all, the choice of over 100 listed companies is unlikely to be wrong.

Choose Voohu – truly reliable. This is not just a slogan, but the answer written with the trust of over 1,500 customers over 8 years.