Novel Concept Dynamic Feedback MCML Technique for High-Speed and High-Gain MCML Type Latch

Tetsuo ENDOH  Masashi KAMIYANAGI  

Publication
IEICE TRANSACTIONS on Electronics   Vol.E92-C   No.5   pp.603-607
Publication Date: 2009/05/01
Online ISSN: 1745-1353
DOI: 10.1587/transele.E92.C.603
Print ISSN: 0916-8516
Type of Manuscript: Special Section PAPER (Special Section on Fundamentals and Applications of Advanced Semiconductor Devices)
Category: 
Keyword: 
dynamic feedback MCML,  MCML,  D-flip flop,  sampling mode,  holding mode,  

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Summary: 
In this paper, we propose the novel Dynamic Feedback (DF-) MCML technique for high-speed and high-gain MCML type latch. The concept of the proposed DF-MCML technique is as follows; the output node signal is feedbacked to the input node in Sampling-Mode, and the output node is opened from the input node in Holding-Mode. It is shown by analytic theory that by this dynamic feedback sequence, both stability and sensibility of latch in Sampling-Mode is exponentially improved, and the gain of latch in Holding-Mode is drastically increased. Finally, we have numerically investigated the circuit performance of the novel DF-MCML type latch in comparison with the conventional MCML type latch by using P-Spice simulator. The maximum operation frequency of 180 nm DF-MCML type latch reaches over 20 GHz that is 2 times than the conventional MCML type latch. It is made clear that the proposed novel Dynamic Feedback MCML technique is suitable for over 10 GHz high-speed and high-gain Si ULSIs.