混沌编码A/D转换器的原理与设计

Chaotic code A/D converter:theory and practice

为了进一步探讨混沌理论在模数转换(A/D)领域的应用,提出一种新型的混沌编码A/D转换电路.该转换电路基于混沌系统的初值敏感性和符号动力学,在考虑运算放大器和比较器失调电流、失调电压的情况下,通过对其非线性动力学分析所得为sawtooth映射.Matlab数值仿真分析了电路映射参数波动时对转换结果所产生的影响.实验结果证实:该混沌编码A/D转换电路初值与轨道距离之间具有较好的线性度;电路采用常用器件,在没有任何模拟补偿及数字补偿的情况下,转换分辨率能达到12位以上,适合于SoC IP设计.

To deeply discuss the application of chaotic theory for A/D conversion, the design theory and practical issue regarding the realization of chaotic code A/D converters are presented in this paper. Based on sensitive dependence on initial conditions in chaotic systems and symbol dynamics, a novel nonlinear cir- cuit was designed. The negligible DC offset of the operation amplifier and comparator showed that it was a sawtooth map after analysis of the nonlinear circuit. The effect of A/D conversion results was studied by Matlab simulation in the case of change of the circuitis mapping parameter. Experiment results indicated that the linear relation between initial values and distances of their orbits is obvious, and that more than 12 bit resolution can be achieved without any digit or analog compensation and use of unexpensive elements. It is appropriate for SoC IP design.