'Industry's first' 4-level Pulse Amplitude Modulation PHYs

By transmitting more bits per symbol, the 28nm BCM82040 and BCM82004 PHYs support higher data throughput over existing low bandwidth channels. The PAM-4 technology enables the transmission of 40Gb/s at a baud rate of 20Gbaud, resulting in improved signal integrity while re-using existing channels for higher data throughput, and allowing the use of lower cost cables and optics. Enabling higher throughput and lower total system cost and power consumption, the PAM4-line code in the PHYs requires half the bandwidth of Non-Return-to-Zero line code.

Both devices are designed to transmit and receive 40/50G data over two pairs of media versus eight pairs of media using existing 4x10G quad small form-factor pluggable cables. In 40G optical applications, the BCM82040 reduces the number of optical components and optical fibres required by a factor of four, further reducing cost and power.

The BCM82040 is optimised for transmitting 40/50Gb/s over optical fibre, while the BCM82004 is optimised for transmitting 40/50Gb/s over DACs. Both devices are available in sample quantities.

"Our PAM-4 PHYs provide a suitable solution for OEMs and data centre operators looking for cost and performance optimisation," commented Lorenzo Longo, Vice President and General Manager, Physical Layer Products, Broadcom. "This latest addition to our product line-up demonstrates our commitment to pioneering technology developments such as PAM-4 and further solidifies our position as the industry leader in wired physical layer devices."