At present, the main products of 400G transceivers are QSFP-DD, OSFP and CFP8. This article introduces: Why 400G QSFP-DD is more popular than 400G OSFP and 400G CFP8

1: QSFP-DD provides maximum port density. This makes QSFP-DD more attractive than OSFP form factor modules and larger CFP8 modules.

2: The power consumption (the maximum power that the module can dissipate without damaging the internal components) is also a very important consideration. In this regard, QSFP-DD also has advantages, and the power consumption mainly comes from the microcontroller and PAM4 DSP. The advent of EUV (Extreme Ultraviolet Lithography) technology will also reduce the power consumption of QSFP-DD logic components in order to ensure that the heat generation of internal components is reduced below the critical level.

3: At the same time, QSFP-DD can also ensure backward compatibility with QSFP slave ports and allow upgrades from 100G QSFP28 systems to 400G capable solutions.

The difference between 400G QSFP-DD fiber optic module and 100G QSFP28 fiber optic module

Compared with QSFP28 of 100G, 400G QSFP-DD is an upgrade of 100G, which is realized by improving DSP and using PAM4. However, it also differs from QSFP28 in that it has 4 additional Tx and Rx channels, and an additional electrical connector needs to be added to ensure space for said Tx and Rx channels. This results in 8 50G PAM4 traffic channels between the Host and the pluggable 400G QSFP-DD. The 400G QSFP-DD SR8 both use 50G PAM4 to convert 8 electrical signal channels to optical channels.

FIBERWDM focuses on the development and manufacture of commercial and industrial 400G, 200G, 100G, 50G, 40G, 25G, 10G, 1.25G optical modules and 3G/12G HD video optical modules. If you are interested, you can contact us!