A high-precision Sigma Delta DAC for audio Codec has been designed.To address the issue of large area occupied by digital interpolation filters,a multiplier multiplexing method has been proposed to reduce hardware consumption in digital circuits.To solve the nonlinear problem caused by multi bit quantization in Sigma Delta modu-lators,the DWA(Data Weight Average)algorithm is introduced to improve the accuracy of the system.In addition,DCT(Direct Charge Transfer)circuits are used to achieve high-precision conversion from digital domain to analog domain.The circuit adopts 0.18 µ m CMOS process,and the overall signal-to-noise ratio of the DAC is 105.7dB@1 150Hz.The effective number of bits reaches 17.26 bit.
NETL
NSTL
万方数据
维普
