Building blocks for a filter tuning system using an analog VLSI fuzzy logic controller

The coverage of the present research is the analog VLSI implementation of a fuzzy logic controller to tune monolithic filters and the software verification of the overall system to tune these filters. The building blocks of the fuzzy controller for filter tuning include a membership function generator, min and max circuits, a second-order low pass filter using BiCMOS transconductance multipliers, analog multipliers, defuzzifiers, and oscillators. The goal of the hardware implementation is to have good programmability, small silicon area requirements, high speed, and low power. Simulation results of all building blocks are in good agreement with the ideal response and verify the high speed operation of the circuit.; Chip measurement results of three analog multipliers, a voltage-mode defuzzifier, a charge-mode defuzzifier, and a second-order low pass filter using a transconductance multiplier, were in good agreement with the simulation results. The analog Orbit 2{dollar}mu{dollar}m low noise N-well MOSIS fabrication technology was used for chip fabrication. The MATLAB implementation for the functional verification of a proposed fuzzy tuning filter system was performed using a simple linear model. The proposed MatLab architecture allows programmable window specifications. A total of 52 rules were used for the fuzzy inference engine based on the results of extensive SPICE simulations of a second-order low pass filter. In most cases of different initial variable settings, the fuzzy logic controller converged to the filter window specifications within at most ten iterations.; The proposed fuzzy filter has two possible implementations. In the first implementation the filter system and fuzzy logic processor can be built on the same chip, while in the second implementation the two blocks can be built on separate chips. The advantage of the single chip implementation is reliability, but at the expense of silicon area. Suitable applications for the single chip are in mass produced items such as television. In the separate chip implementation, one fuzzy logic processor chip can be used to tune any number of filter system chips. In this approach, each filter will be tuned with one chip which will be programmed in advance and a circuit to compensate for temperature variations must be included in each chip.