Low-power multi-GHz silicon germanium FPGAs for reconfigurable computing.

摘要

The Silicon Germanium (SiGe) Heterojunction Bipolar Transistor (HBT) is the first successful bandgap engineered device. It has a comparable performance to a Gallium Arsenide (GaAs) Radio Frequency (RF) device, but it can be fabricated at a significantly lower cost. The smaller base bandgap of SiGe compared to Si enhances electron injection, producing higher current gain for the same base doping level compared to Si devices. SiGe HBT and Si CMOS can be grown over the same substrate because these processes have strict compatibility with existing CMOS tool sets and metallization schemes. SiGe HBT has emerged from research to become a leading contender in the RF market. State-of-art of SiGe can deliver: (1) fT in excess of 207 GHz; (2) minimum noise figure; (3) cryogenic operation; (4) reliability comparable to Si.; The demand for high speed Field Programmable Gate Arrays (FPGAs) has always been on the rise. This was never possible using CMOS as the basic device. People were able to achieve frequencies in the range of 10--500 MHz using CMOS. The availability of SiGe HBT devices has opened the door for Gigahertz FPGAs. The integration of these high-speed SiGe HBTs and low power CMOS gives a significant speed advantage to SiGe FPGAs compared to traditional CMOS FPGAs.; This thesis will concentrate on how to minimize power consumption in SiGe BiCMOS mixed-signal FPGAs, and the combination of Analog-Digital Converters (ADCs) and deserializers together with the FPGA. In particular, a description of how to merge circuits to reduce power dissipation will be provided. A new circuit topology will be presented that can effectively achieve a flexible trade-off between power and circuit speed. In addition, the development of an X-pattern decoding logic with shared address and data lines that alleviates the line congestion will be discussed. Beyond this, several deep trench sharing techniques, developed to shrink the layout areas, will be shown. Six SiGe FPGA test chips based on the Xilinx 6200 and Virtex architectures have been fabricated for demonstration using IBM SiGe 5HP, 7HP and 8HP technologies. The design of several high speed FPGA based applications will also be presented.