Research On Digital Filter For Oversampling D/A Converter

With the rapid development of information technology, and that of the extraordinary advancement of VLSI technology, the digital signal processing has gained a great deal of achievement. As one of the basic ways in digital signal processing area, digital filtering has gained wide application and a lot of focus due to its accuracy, flexibility and large scale integration.This paper begins with digital interpolation filter in oversampling DAC, profoundly discusses approaches to design of FIR digital filter with linear phase, and focuses on how to effectively implement 2x interpolation filter using VLSI technology.Firstly it discusses the technology of sampling rate conversion in digital signal processing area and its application in A/D and D/A, emphasizes on analyzing the function of 2x interpolation in D/A converter. Secondly, it compares three approaches of designing FIR digital filter with linear phase and finishes its design. Then it design-s the 2x interpolation filter using the optimization approach with equivalent ripple. Due to finite word length effect in hardware implementation, it quantizes coefficient of filter, and analyzes the effect of quantization toward performance of filter.It focuses on the research of VLSI implementation of digital filter. It optimizes the architecture of 2x interpolation filter, and fully discusses key problems in the design of constant-coefficient multipliers; the optimized architecture of filter it presents and CSD encoding of coefficient, largely reduce the hardware cost of the filter; carry lookahead adder and Wallace compression tree, it utilizes effectively improve the calculation velocity of the digital filter; Additionally, Due to the consideration of DFT, the Build-in-self-test in the design resolves the problem of chip's testability.Finally, the simulate results have testified the correctness of 2x interpolation filter in this thesis.