Spectral impact of the modulation index upon internal log-domain currents

This brief investigates quantitatively the impact of the input-signal modulation index upon the spectral content of internal log-domain currents. A second-order log-domain topology is treated as an example circuit and the quantitative dependence of the harmonic contributions to the total harmonic content of current signals internal to the topology upon different levels of strength of applied input tones is illustrated. Subsequently, this frequency-domain information is correlated with the transition frequency of the active devices which carry the nonlinear currents providing a certain degree of quantitative design insight.

[1]  A. J. Payne,et al.  A Bernoulli Cell-Based Investigation of the Non-Linear Dynamics in Log-Domain Structures , 2000 .

[2]  Yannis Tsividis,et al.  Mixed analog-digital VLSI devices and technology , 1996 .

[3]  D. Frey.  Exponential state space filters: a generic current mode-design strategy , 1996 .

[4]  Robert M. Fox.  Enhancing dynamic range in differential log-domain filters based on the two-filters approach , 2000, 2000 IEEE International Symposium on Circuits and Systems. Emerging Technologies for the 21st Century. Proceedings (IEEE Cat No.00CH36353).

[5]  D. R. Frey.  Log domain filtering for RF applications , 1996 .

[6]  Paolo Antognetti,et al.  Semiconductor Device Modeling with Spice , 1988 .

[7]  Kenneth R. Laker,et al.  Design of analog integrated circuits and systems , 1994 .

[8]  C. Toumazou,et al.  "Log-domain state-space": a systematic transistor-level approach for log-domain filtering , 1999 .

[9]  Christian Enz,et al.  Low-voltage log-domain signal processing in CMOS and BiCMOS , 1999 .

[10]  W. R. Eisenstadt,et al.  Dynamic currents in log-domain filters , 1999, 42nd Midwest Symposium on Circuits and Systems (Cat. No.99CH36356).

[11]  A. C. van der Woerd,et al.  General current-mode analysis method for translinear filters , 1997 .

[12]  Emmanuel M. Drakakis,et al.  Log-domain filtering and the Bernoulli cell , 1999 .

[13]  Yannis Tsividis,et al.  Externally linear, time-invariant systems and their application to companding signal processors , 1997 .