Modular analysis and design of log-domain circuits based on LIN↔ELIN transformations

• Published in: Analog integrated circuits and signal processing 2007-03, Vol.50 (3), p.231-249
• Main Authors: Feştilă, L., Groza, R., Cîrlugea, M., Fazakas, A.
• Format: Article
• Language: English
• ISSN: 0925-1030; 1573-1979
• DOI: 10.1007/s10470-006-9014-8

We systematized and developed some procedures for the modular design of externally-linear internally nonlinear (ELIN) circuits resulting in a general LIN{left-right arrow}ELIN transformation procedure. This one was also extended to analysis of these types of circuits. The procedure is exemplified on log-domain circuits. In the design one starts with the linear block diagram (LIN) described by transfer functions and one substitutes directly each linear building block by a corresponding nonlinear one. The parameters of each nonlinear component depend on the given parameters of its linear correspondent. Input F and output F blocks are added. In the analysis one identifies the nonlinear basic circuit components and each of them is substituted by its corresponding linear building block. Input and output F -F cells are removed. The ideal transfer function can be calculated on the linear block diagram now. The LIN{left-right arrow}ELIN transformations make a direct connection between equivalent linear and ELIN circuits, simplify their design and analysis procedures and permit the development of CAD procedures.