Novel concept dynamic feedback MCML technique for high-speed and high-gain MCML type latch

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.