The Design And Implementation Of Multi-channel Signal Sources Based On FPGA And DDS

At electronic measurement technology, almost all of the electrical parameters of the testuse a signal source as an incentive. According to characteristics of the telemetry acquisitionchannel, carried out around its static and dynamic characteristics of the testingrequirements.The direct current component signal with high precision can be served as a staticfeature of the testing equipment and the rectangular wave signal can be served as a dynamicproperty. The author has designed a mechanism and approach that is based on multi-routesignal sources of FPGA and DDS.The signal source in question can transmit 32 routes of signals parallelly and provide 5types of wave signal, including Sinusoid, sawtooth wave, triangular wave, rectangular waveand direct current component, and the frequency and amplitude of the output signal can beadjusted by the top position. Which type of signal waveforms sine wave, sawtooth, trianglewave, square wave and direct traffic types to choose from. According to the testingrequirements, a source of technical indicators: AC output frequency is 1Hz ~ 1KHz rangeadjustable; the output amplitude of the 0V~~ +5 V-adjustable; rectangular wave edge of thetime <1μs. Direct flow output amplitude is-1V to +7 V,the output signal of an accuracy of0.1%.For the purpose of testing, the author has brought up a multi-route signal source withhigh precision that combines the mechanism of DDS and the advantage of FPGA which is ahigh speed, programmable logic gadget. The signal source is featured with all of theprominent advantages of FPGA and DDS, and realizes the optimization of the DDS withinFPGA. Also, the author has successfully optimized the DDS with multithreading of the timesequence. Moreover, the author has creatively designed an internal programming of FPGA totest and transform the way that the amplitude can be adjusted.The author has conducted athorough theoretical analysis and quantitative description of the major technologies of thesignal source before the designing of the hardware. And after finishing of the debugging of the circuit of the hardware, the experiment results support the analysis.The experiment has proved that the signal source can produce various channels that cansimultaneously export signals with different waves frequencies and amplitudes, and can meetthe requirements of the task which is characterized by stable outputs, high precision, wideamplitude, low costs, flexibilities in designing, high integration and expansibility, etc.