Transceiver IC encourages serial links

-- EDN, 2/17/2000

The eternal parallel-versus-serial-backplane battle continues with the 21Z01 transceiver from Aanetcom Inc (Picture). The device provides eight independent serial channels at speeds as high as 1.25 Gbps each. It includes the standard 8B/10B block-coding logic, compatible with 802.3z Ethernet and Fibre Channel mandates, using internal parallel/serial and serial/parallel functions along with FIFO memory, synchronization to a local clock, and loop-back and built-in-self-test functions.

The 2.5V, 3.3V-tolerant IC typically consumes 1.25W. The 8B/10B encoder in the device, which you can disable for your own coding scheme, ensures that the data stream has a bit transition every five bit periods. This approach facilitates clock recovery from the serial data stream at the receiver and balances baseline wander to minimize error-inducing conditions. If you want to further pump up your serial data rate, you can use the transceivers' "trunking" function, which allows you to combine all output channels into a single 12.5-Gbps channel. The 208-bump BGA device, which has a 15x15-mm footprint, costs $48 (1000).

Aanetcom Inc, www.aanetcom.com.

-by Bill Schweber