Transceiver spits terabits, sips milliwatts
-- EDN, January 4, 2001
Extending the architecture of its four-channel BBT3400 transceiver, BitBlitz Communications is offering an octal, full-duplex, 3.125-Gbps-per-channel trans- ceiver. The low power BBT-3800, intended for serial-backplane applications in Internet routers and terabit switchers, drives high-speed copper and OC-192, DWDM (dense-wavelength-division-multiplexing), and InfiniBand optical links.
The BBT3800 supports one operating mode that allows the eight full-duplex channels to operate independently (Picture). A second mode implements two independent 25-Gbps extended-attachment-unit-interface channels for 10-Gbit Ethernet. The third mode de-skews eight transmitting and eight receiving lines for an aggregate 50-Gbps bandwidth. The transmitters include a 4-byte FIFO buffer, an 8b/10b encoder, and a serializer. Receivers perform clock recovery, deserialize and decode the 8b/10b data, and feed a 16-byte FIFO. A built-in loop-back system facilitates self-test, and a bytewide system-side loop allows a transceiver to operate as a repeater.
The 676-contact BGA-packaged device dissipates 163 mW per channel from a 1.8V supply when configured for the HSTL (high-speed-transceiver-logic) parallel interface. When operating with an SSTL (stub-series-terminated-logic) interface, the transceiver requires an additional 2.5V, supply but the dissipation rises only to a cool 200 mW per 3.125-Gbps full-duplex channel. The part also implements the proposed IEEE 802.3ae serial-management interface. The BBT3800 eight-channel transceiver costs $135 (1000); the four-channel BBT3400 costs $70 (1000) in a 289-contact BGA package.
BitBlitz Communications, www.bitblitzcom.com.
-by Joshua Israelsohn
