A FPGA-based 7-order 1-bit Sigma-Delta Modulator for High-precision Signal Generation
This paper presents a design of a FPGA-based 7-order 1-bit sigma-delta modulator with zero points residing in noise band. The modulator, incorporating with a 24-bit sine wave source, a 1-bit DAC and a subsequent reconstruction filter, generates a signal to test a high-precision sigma-delta ADC. The test signal, which contains both sine wave and high frequency noise, is sampled by the ADC under test. Usually, the noise in the test signal can not be fully suppressed by subsequent decimation filters of the ADC. So decimation filters should be taken into account for designing the modulator. To compensate for the noise suppression limitation of the decimation filters, zero points are introduced to the noise band of the modulator noise transfer function (NTF). With the adding of these noise band zero points, the SNR of ADC output data reaches 115dB in the range of 0500Hz, which is about 10dB higher than that of a system without these zero points.
zero points sigma-delta modulator noise transfer function FPGA.
Song Hongzhi Wu Jie Ma Yichao Kong Yang Zhang Jie
Department of Physics,University of Science and Technology of China Key Laboratory of Technologies o Department of Modern Physics,University of Science and Technology of China Key Laboratory of Technol
国际会议
2009 9th International Conference on Electronic Measurement & Instruments(第九届电子测量与仪器国际会议 ICEMI2009)
北京
英文
3388-3392
2009-08-16（万方平台首次上网日期，不代表论文的发表时间）