关键词: F/V转换;精度;FPGA;Q8定点运算;DAC7551

Abstract:

A linear F/V converting system is designed.The pulse frequency signal generated by the sensor is sent to FPGA after being conditioned by the signal conditioning circuit,and then FPGA measures the frequency of the signal.The system precision requirements require a design of Q format fixed-point arithmetic.The measured frequency obtained by the FPGA fixed-point arithmetic is linear with the digital value of DAC which controls DAC7551 output the corresponding voltage.The experimental results show that the system of conversion precision is better than 0.1%.Changing the system design parameters can achieve a more precise frequency signal to the voltage signal conversion.

Key words: F/V converting;precision;FPGA;Q8 fixed-point arithmetic;DAC7551