San Jose, California-based Micro Linear Corp claims to have the first fibre optic Ethernet chip set for the emerging 10Base-FL standard, saying that it implements all the features in the proposed standard, making it possible to connect personal computers to Ethernet fibre optic cables. The set comprises ML4622 Fibre Optic Data Quantiser and ML4662 10Base-FL Transceiver. The quantiser receives low-level signals down to 2mV from a fibre optic receiver and converts them into a clean digital waveform for the transceiver, and is a general purpose device that can also be used in of fibre-optic Token Rings. The ML4662 transceiver was tailored specifically for 10Base-FL and detects collisions and directly drives received waveforms over the Attachment Unit Interface cable to the Ethernet controller. The transceiver also filters out the 1MHz idle signal that is on the fibre optic cable when no data is being transferred. In transmit mode, the transceiver generates and sends the 1MHz idle signal required when the transmitting unit is not sending data. It also includes a current-driven light-emitting diode driver, which directly drives the fibre optic LED with the 10Mbps data stream provided by the Ethernet controller chip. Using fibre optics enables cables to be up to 6,000 feet long without repeaters, as well as conferring security and radiation immunity on the network. The ML4622 is $7 for 1,000 or more and the ML4662 at $19.50 for 1,000-up.
