Data Bus Deskewing Systems in Digital CMOS Technology

Deskew;Skew;PCB;TDR

Atrash, Amer Hani ; Electrical and Computer Engineering

University:Georgia Institute of Technology

Department:Electrical and Computer Engineering

关键词: Deskew;    Skew;    PCB;    TDR;   

Others  :  https://smartech.gatech.edu/bitstream/1853/4969/1/atrash_amer_h_200407_phd.pdf

美国|英语

来源: SMARTech Repository

【 摘 要 】

This dissertation presents a study of signal deskewing systems in standard CMOS technologies. The objective of this work is to understand the limitations of deskewing systems as they are applied to modern systems and present new architectures to overcome past limitations. Traditional methods for signal deskewing areexplored and the general limitations of these methods are identified. Several new architectures are proposed to address the limitations of previous techniques. Thesystems will be investigated with regard to minimum resolution, programming time,delay, maximum data rate, full scale range, and duty cycle distortion. Several othereffects that are critical to the operation of deskewing systems will also be investigated.These effects include overshoot caused by parasitic package inductance, the impactof capacitive terminations, and the effect of mutual inductance between traces.To fulfill the requirements of this study, two deskewing systems are implementedin a 0.25um process. An open-loop system for deskewing wide data busses and aclosed-loop system for deskewing a differential pair of lines are both fabricated. Bothsystems are found to meet the expected performance metrics, providing validation ofthe proposed techniques. Use of the proposed architectures allows the limitations ofprevious methods to be overcome. The remaining work is validated through either analytical techniques, simulations, or both where appropriate.