How to choose a DAC high-speed cable?

DAC high-speed cable is a low-cost short distance connection scheme for data center equipment. It consists of cable and optical transceiver at both ends of the cable. Due to its high cost performance, it is widely welcomed in the interconnection application between short distance network equipment. At present, there are many specifications of DAC high-speed cables on the market.

1. There are two types of high-speed cables: active and passive. The difference between the two is that the active DAC high-speed cable has an additional driver chip. At the same time, the active optical cable does not need power skills to display its characteristics, while the active optical cable needs external power to display its characteristics.

In general, when the transmission distance exceeds 5 meters, the active DAC high-speed cable is the most appropriate choice to reduce signal interference. Passive high-speed cables will not amplify and equalize optical signals during transmission.

While the active high-speed cable transmits optical signals, it also amplifies them to increase the transmission distance. Therefore, the transmission distance of active high-speed cable is longer than that of passive high-speed cable, but its price is also more expensive.

2. When purchasing, we need to determine the cable length and AWG value. The common AWG values of high-speed cables are 24AWG, 28AWG and 30AWG.

Because the AWG24 is thicker and heavier than the AWG30, the longer the AWG24 is, the less convenient it is to use the AWG30, and the bending sensitivity is limited. Therefore, in long-distance transmission, it is appropriate to choose AWG with larger value.

3. Determine the transmission rate and connector type. According to different transmission rates, DAC high-speed cables can be divided into 10G SFP+DAC high-speed cables, 25G SFP28 DAC high-speed cables, 40G QSFP+DAC high-speed cables and 100G QSFP28 DAC high-speed cables, which are mainly used for direct connection of short distance equipment in the data center.

In addition, in order to meet the user's network upgrade needs, the 40G QSFP+DAC high-speed cable and the 100G QSFP28 DAC high-speed cable are equipped with branch cable packaging, which can be used in the 40G to 4 * 10G and 100G to 4 * 25G network upgrade application scenarios.