David W. Siljenberg

An integrated 1.25 Gbit/s laser driver/post amplifer IC

This paper presents the first reported integrated 1.25 Gbit/s post amplifier and laser driver, to the authors knowledge. The post amplifier amplifies 20 mV signals from a pre-amplifier and provides redundant loss of signal detectors. The laser driver provides up to 100 mA DC drive and 25 mA/sub p-p/ C drive. This presents a large on chip isolation challenge and 79 dB of isolation was achieved. The chip has sufficient redundancy and error detection to provide international Class 1 laser safety certification. The chip operated up to 1.6 Gb/s. The design is implemented in a 0.45 um L/sub eff/ BiCMOS technology with 12 GHz NPNs. It is packaged in a 48 lead 7 mm plastic quad flat pack surface mount package.

Xbox360 Front Side Bus - A 21.6 GB/s End-to-End Interface Design

With a bandwidth of 21.6 GB/s, the front side bus (FSB) of the Microsoft Xbox360trade is one of the fastest, commercially available front side bus interfaces in the consumer market. This paper explains the end-to-end system approach used in designing the bus that achieved volume production ramp 18 months after design start. The 90 nm SOI-CMOS CPU and 90 nm bulk CMOS GPU designs are described. The chip carrier, circuit board, and signal integrity analyses are described. The design approach used to achieve high volume, low cost, and short development time is explained.