PORTLAND, Ore. Silicon germanium design house Ensphere Solutions Inc. (Santa Clara, Calif.) cranked up its complementary metal oxide semiconductor (CMOS) expertise to design a 10-Gbit/second, dual-channel optical-to-electrical and electrical-to-optical transceiver chip for Intel's Light Peak topology.
Light Peak interconnects computers, displays, disk drives, docking stations, printers, Webcams, handsets and more with a lightweight daisy-chained optical cable running the native I/O protocols for each device, but executing them at 10 Gbits/s over a common optical fiber.
Ensphere's main business has been contract design work, but it branched out into standard products last year with a line of chips that includes a 10-Gbit/s electro-optical transceiver cast in 180-nanometer silicon germanium (SiGe) BiCMOS. For its Light Peak transceiver chip, Ensphere chose to push the envelope by going with 65-nanometer CMOS.
"We were used to 10-Gbit transceivers costing $50 or more," said vice president of marketing Al Gharakhanian. "But to get to the $10 price point you need for consumer devices, we had to go with standard CMOS, then work hard to meet the specifications for a 1012 bit error rate and a 135-milliwatt-per-channel power budget."
Intel is working with industrial partners like Ensphere for the various components of its optical interconnection technology. Sony is putting Light Peak on its Vaio notebook computers to allow them to interface with a variety of peripherals using the same optical connector. Avago Technologies Inc. (San Jose, Calif.) has developed an extra-thin-profile, 2-mm optical connection to its embedded optical engine for Light Peak. IPtronics A/S (Roskilde, Denmark) has announced a vertical-cavity surface-emitting laser (VCSEL) for transmission and a photodiode (PiN, for p-type/intrinsic/n-type), for reception. Intel itself is supplying the controller chip that interfaces devices to the electrical side of the Ensphere chip.
"We had to work closely with Intel to meet its specifications for the electrical interface to their own controller chip, and on the optical side to be compatible with the VCSEL and PiN," said Gharakhanian.
The dual channels on the Ensphere chip permit Light Peak to function like an optical local-area network (LAN) that has no native protocol but instead allows multiple existing electrical protocols to coexist on the same 10-Gbit/s fiber. By daisy-chaining the optical cable from device to device, each data stream can originate and terminate at different locations along the fiber simultaneously. For instance, a connection from a computer to a display using DisplayPort can coexist on the same optical cable with a DVD player streaming a movie over HDMI.
Intel's controller will concentrate the data from devices using different protocols into a single stream, route it from the optical fiber to the right device, then split off the data intended for a particular device when the stream arrives at its destination.
Ensphere's transceiver chip, the ESI-XVR10100, measures about 1.7 x 0.7 mm and houses dual channels, each with a transmitter and receiver, permitting an OEM to use one channel to connect to its device and the other to pass data down the daisy chain. The chip is supplied as a bare die that is wire bonded to the printed-circuit board holding the PiN and VCSEL chips, thereby forming a complete electro-optical transceiver module.
Ensphere's chip supports multiple diagnostic modes and a variety of power management modes. Samples are available now; production quantities are expected by the end of the year.