Figure 5. Non-linear integrator with ideal non-linear components. (o) is the reference signal, (...) is the output of the non-linear plant and (+) is the compensated signal Vi Vo R R Figure 6. Non-linear integrator used for validation Figure 7 - FFT of the non-linear output (a) and output of the compensated signal (b). Figure 8 - Results of the plant trained with a sinus. Our future work involves a concrete evaluation of the area power trade off of the smart sensor non-linear compensation using this technique, and to expand this work to cope with some non-linear characteristics of the AD converter as well. 7 . References [1] TSIVIDIS, Y.; BANU, M.; KHOURY J. Continuos-time MOSFET-C Filters in VLSI. IEEE Journal of Solid-State Circuits, v.21, Feb. 1986. pp.15-30. [2] ISMAIL, M.; SMITH, S.; BEALE, R. A New MOSFET- C Universal Filter Structure for VLSI. IEEE Journal of Solid- State Circuits, v.23, n.1, Feb. 1988. [3] SILVA-MARTINEZ, J.; STEYAERT, M.S.; SANSEN, W. Design Techniques for High-performance Full-CMOS OTA- RC Continuos-Time Filters. IEEE Journal of Solid-State Circuits, v.27, n.7, Jul. 1992. p.993-1001. [4] BULT, K.; GEELEN, G. J.G. M. An Inherently Linear and Compact MOST-Only Current Division Technique. IEEE Journal of Solid-State Circuits, v.27, n.12, Dec. 1992. p.1730. [5] BERMUDEZ, J.; SCHNEIDER, M.; MONTORO, C. Compatibility of switched capacitor filters with VLSI process. Inst. Elect. Eng. Proc., -G, v.139, Aug. 1992. p.413-418. [6] TSIVIDIS, Y. Externally Linear, Time-Invariant Systems and Their Application to Companding Signal Processors. IEEE Transactions on Circuits and Systems, II: Analog and Digital Signal Processing. v.44, n.2, Feb. 1997, p.65-85. [7] HOSTICKA, B.J. Integrated Sensor Systems in CMOS Technology. In: Analog Circuit Design, Van DE PLASSCHE, R.; HUIJSING, J.; SANSEN, W. Kluwer Academic Publishers, Dordrecht, The Netherlands, 1997. p.219-241. [8] TRAVIS, B. Smart Sensors. EDN, May 1996. p.57-65. [9] BRYZEK, J.; RASTEGAR, A. Advances in state-of-the- art in smart sensor signal conditioning. In: Analog Circuit Design, Van DE PLASSCHE, R.; HUIJSING, J.; SANSEN, W. Kluwer Academic Publishers, Netherlands, 1997. p.123-149. [10] HÄBERLI, A.; BALTES, H. Compensation and calibration of IC Microsensors. In: Analog Circuit Design, Van DE PLASSCHE, R.; HUIJSING, J.; SANSEN, W. Kluwer Academic Publishers, The Netherlands, 1997. p.243-267. [11] VAN DER HORN,G.; HUIJSING, J.H. Integrated Smart Sensor Calibration. Analog integrated circuits and signal processing, v.14, n.3, Nov. 97, pp.45-60. [12] HILLE, P.; HÖHLER, R.; STRACK, H. A linearization and compensation method for integrated sensors. Sensors and Actuators, v. A44, n.2, Ago. 94, p.95-102. Elsevier, 1994. [13] IGLESIAS, G.E.; IGLESIAS, E.A. Linearization of transducer signals using an Analog-to-digital converter. IEEE Transactions on Instrumentation and Measurement, v.37, n1, Mar. 1988. p. 53-57. [14] ANALOG DEVICES. ADXL05 Reference Manual. Analog Device Inc. 1996. [15] DOEBELIN, E. Measurement Systems.McGraw-Hill, New York, 1983. pp.876. [16] SEDRA, A. S.; SMITH, K. C. Microelectronic Circuits. Sauders College Publishing, Philadelphia, PA, 1991. pp. 1054. [17] HAYKIN, S. Adaptive filter theory. 2.ed. Englewood Cliffs, N.J.: Prentice-Hall, 1991. 854p. [18] MULGREW, B.; COWAN, C. F. Adaptive Filters and Equalisers. Kluwer Academic Press, 1988. [19] WIDROW, B.; STEARNS, S.D. Adaptive signal processing. Englewood Cliffs, N.J.: Prentice-Hall, 1985. 474p. [20] MATHEWS, V.J. Adaptive Polynomial Filters. IEEE SP Magazine, July 1991, p.10-26. [21] SICURANZA, G. L. Theory and Approximation of Polynomial Filters. In: IEEE Circuits & Systems Tutirials, ISCAS’ 94. Edited by C. Toumazou. IEEE, 1994, England. Chapter 1.21, p.50-58. [22] WIDROW, B.; WALACH, E. Adaptive Inverse Control. Prentice Hall, New Jersey, 1996. p.508. [23] HAHM, M.; FRIEDMAN, E. G.; TITLEBAUM, E.L. Analog vs. Digital: A comparison of circuit implementations for low-power matched filters. IEEE ISCAS’96 proceedings p.280.