The Research On High Voltage Signal Source Based On FPGA

Studies in iron-dielectric material, the polarization and theinversion for the ferroelectric material requires a higher voltage,so the signal source which has a high output voltage is required, currently on the market the normal signal source output voltage is 5Vpp generally, which can not meet the problem of the use for studies obviously, for this problem, the paper presents a method,which uses FPGA based on the technology of direct digital frequency synthesis(DDS) to develop a high voltage source source.Design the high voltage source is divided into two parts, one is the development of FPGA arbitrary waveform generator, the other is to boost and amplify the output power. Arbitrary waveform generator design is based on the technology of the programmable logic devices.After the introduction of DDS,the method to design the system is puted forward.The hardware description language Verilog HDL is used to design the DDS.Because of the problem of the shortage of the ROM resources,the technology of DDS ROM compression is used to solve the problem.For the different wave,the different method is used for the compression of the ROM,and the final proportion of compression can reach 16: 3, but the circuit only adds a counter and an inverter, the problem is sloved finaly.The control unit for the signal uses the technology of SOPC, the soft-core of N ios II is used to control the DDS waveform signal source、the LCD screen, as well as the acquisition of the control signal to the keyboard.In the design of the control unit, the paper focuses on the N ios II HAL system development environment, shows the flow chart of the LCD and keyboard control, and use C language design procedures.The technology of floating voltage source is used in the signal booster module, which pull the the voltage of the operational to± 20 V from ± 15 V, the final design is a amplifier belongs to the class of AB which is drived by a operational amplifier,and the operational amplifier uses the floating voltage source,the problem of crossover distortion is sloved at the same time.Final test results show that the system can output sine, triangle, sawtooth and variable duty cycle square wave signal,and the frequency is adjustable from 0 to 1Mhz,the minimum resolution is 0.023 Hz theoretically.The measured minimum frequency is less than 1Hz, output peak to peak voltage up to 40 Vpp.