Primus IT Releases Technical Interpretation of 50G PAM4 Optical Transceiver

As data demands increase and hyper-scale data centers proliferate, operators, enterprises and serviceproviders are looking for more economical Ethernet solutions. PAM4 technology can effectively increasebandwidth utilization efficiency and thus reduce costs. 25Gbaud PAM4 is now in the market, it is planned toupgrade to 50Gbaud in 2019.

The difference between NRZ and PAM4

The optical components of the PAM4 transceiver are different from those of the NRZ transceiver. The maindifference is the laser driver chip, the TIA chip and the data processing chip.

An NRZ signal uses high and low signal levels to represent 1 and 0 in digital logic signals. Within each clockperiod, one bit of logical information can be transmitted.

A PAM4 signal uses four signal levels for transmission. Within each clock period, two bits of loqicinformation, that is, 00, 01, 11, and 10, can be transmitted.

PAM4' s appeals and advantages:

PAM4 modulation is more suitable for short distances in most data centers. With more complex DSPs andamplifying DWDM system architecture, 25Gbaud’s PAM4 can also be used to transmit 40 channels over 80<ilometres of 100G data. These products and demonstrations clearly demonstrate that PAM4 is well suitedfor new internal data center and data center internal applications because of its combination of high

bandwidth and medium cost

The single-mode 25GB / s NRZ technology solution includes DFB drivers, TIA and CDR, and is mainly usedin QSFP28-CWDM4 and OSFP28-PSM4 optical transceivers in current data centers.

The multimode 50GB/s PAM4 technology solution is the industry’s first dual-channel 100G high-speedoptical interconnect transceiver chipset based on PAM4 CDR technology. Compared to the existing (DSP +inear drive/amplifier) solution, the PAM4 CDR solution has extreme Great cost and power advantages.

400GE / 200GE / 50GE based on single-channel 50G PAM4 technology can well adapt 5G’ s network costand performance requirements, and build an optimal solution from access and aggregation to the corenetwork.

Primus IT has completed the development of the 50G QSFP28 LR / ER:

Primus IT 50G OSFP28 PAM4 LR / ER has been developed and samples will be released in June 2019. Pleasecontact sales@primus-it.com for information.

At the same time, our company is developing 100G OSFP28 PAM4 DWDM, samples will be released beforeOctober 2019.