Propagation delay of an RC‐circuit with a ramp input: An analytical very accurate and simple model

Abstract

SUMMARYIn this letter, one of the models reported in Mita et al. (IEEE Trans. Circuits Syst.-II: Express Briefs 2007; 54(1):66-70) for estimating the propagation delay of an RC-chain with a linear input is revised and improved. The extended model, while maintaining the same simplicity, has a reduced error which is six times lower than the original model, being always as low as 1%.

Simple and Accurate Model for the Propagation Delay in MCML Gates

“…The input step, however, can be considered as ideal if the logic gate is driven by a logic gate of a similar size. Indeed, as demonstrated in [38,39] and shown in Figure 3, if we assume the input signal as a linear ramp with rise time, T, as long as T ∼ τ o , the error between the actual PD and the value estimated by (3) remains lower than 20%. Conversely, (3) fails to predict the PD if the rise time of the input step is significant (i.e., T τ o ), as in the case of a large logic gate driven by a minimum size one.…”

“…However, this case is generally avoided in practical design; in the vast majority of cases, we can assume the input step as ideal. The rise time and the propagation delay are normalized with respect to the time-constant of the single-pole system [38,39].…”

Flip-Flop Design in Nanometer CMOS

“…where C i is the i-th capacitance in the RC tree and R ik is the total resistance shared by the paths between the source node and nodes i and k [31,89,90,125,142] (the resistances R ik are the sums of stacked transistors resistances, and the capacitances C i are the inter-nodal capacitances). Indeed, stacked transistors can be approximated by a simple RC ladder structure (which is a particular case of an RC tree) and the source voltage is given by V DD or ground nodes.…”

P‐31: Novel Calibration Methods to Calculate the Effective Capacitance of Gate line in LTPS Display

“…As we all known, the RC loading of gate lines in LTPS panel can be equivalent to a one-dimensional RC-chain circuit. In 1947, Elmore model [1] was raised to solve the transient response of linear networks of RC circuit, and after that some reports [2][3] presented to modify and optimize Elmore model, and some scientists [4][5] also have proposed new ways to solve this problems. But most of them are not as simple and practical as Elmore Model.…”