Mon. Jun 17th, 2024

How 10GBASE-T RJ45 SFP+ Works

The 10GBASE-T RJ45 SFP+ module is applied to the 10 Gigabit Ethernet switch. Unlike the 10 Gigabit optical module, the module directly transmits the 10 Gigabit differential signal transmitted from category 6 or category 7 twisted pair into the module through the RJ45 port. The differential signal with the rate of 10Gbps first passes through the network isolation transformer, which will filter and shape the external signal. In order to ensure that the differential signal entering PHY is complete and clean, the signal will pass through a series of filter circuits after passing through the network transformer, and then input to PHY. PHY decodes the data and then outputs it. The interface between the module and the switch is the SFI interface. The normal operation of PHY requires a reference clock and a memory chip to configure the PHY register when PHY is powered on. The schematic diagram of the 10GBASE-T SFP+ module is shown in the figure below.     


10GBASE-T SFP+ Transceiver Working Diagram

Form Factor Design of 10GBASE-T RJ45 SFP+

The 10G module has experienced the development of 300PIN, xenpak, X2 and XFP, and finally realizes the transmission of 10G signal with the same size as SFP. This 10G Optical module is 10G SFP+. With its advantages of miniaturization and low cost, SFP+ meets the demand for high-density optical modules. At present, 10G modules and 10G SFP+ form factor in the market have almost completely occupied the market. The reference standard for SFP + packaging is SFF-8432. The SFP+ assembly cage matched with the 10G SFP+ optical module on the Ethernet switch is designed according to SFF-8432 protocol standard. Therefore, if a 10G RJ45 SFP+ electrical interface module wants to be applied to a 10 Gigabit switch, its package size also needs to be designed in strict accordance with SFF-8432 standard. The determination of module shell size determines the size of 10G electric port module PCB accordingly.

The form factor size of SFP+ module greatly improves the design difficulty of the 10GBASE-T RJ45 electric port module. The 10G electrical interface module needs to integrate a physical layer chip to complete the physical layer function of the module. The 10G network transformer isolates and shapes the external signal, and the high-density filter network ensures the signal integrity. A passive crystal provides a reference clock for the physical layer chip, and a memory stores the configuration information of the physical layer chip. Four power conversion chips provide the voltage required by the whole circuit, and a central control unit converts the communication data bus. Therefore, each chip needs to choose the smallest size on the basis of ensuring the basic performance.

The form factor size of 10GBASE-T RJ45 SFP+ is shown in the figure below. Since the RJ45 port needs to be connected with the RJ45 crystal head, in order to plug and unplug the network cable conveniently, the RJ45 port is leaked outside the SFP+ assembly cage. This design can increase the volume of the PCB board and facilitate the layout of the board. Except for the RJ45 port, the size of the tube body of the shell is designed in full accordance with SFF-8432 protocol standard. The module is locked in the SFP+ assembly cage by a latch as shown in the figure below. When the module needs to be pulled out, just pull the pull ring down to unlock it.

10GBASE-T SFP+ Form Factor Structure and Size


In order to integrate the advantages of high flexibility and high density of SFP+ modules into 10GBASE-T, this paper studies the working principle and form factor structure design of SFP + electrical interface modules which can be applied in 10 Gigabit Ethernet switches. The module realizes the data transmission rate of 10Gbps over CAT6A twisted pairs. The specifications of the 10GBASE-T RJ45 SFP + module provided by QSFPTEK are as follows. The working temperature is 0 ~ 85 ℃, the transmission cable is 30m over unshielded CAT6A, the transmission rate is 10Gbps, the power consumption of the module is less than 3.5W, and the module supports the temperature reporting function. QSFPTEK also provides high quality 1000BASE-T SFP transceivers at a low price. Welcome to consult via [email protected].