Miniaturized High Precision Time Interval Measurement Technology Based on FPGA

In this paper, a kind of miniaturized time interval measurement system with high precision, high stability is designed and implemented. In the system, electronic counting method and time-to-voltage converter method are combined together to meet the requirements of the measurement range and the measurement resolution; the reference signal is used to generate calibration signals to automatically calibrate the analog circuit which is greatly affected by the temperature; the calibration data is used to correct the conversion coefficient between voltage and time interval in the software, and as a result, the effect of the temperature on the instrument reduce a lot; the double counter synchronous measurement technology working under two different frequency clocks is adopted and the logic algorithm is used to analyze and correct the measured results to avoid gross error caused by the false trigger of the counter. The whole system is realized on the FPGA. And the experiment result shows that the circuit board area of the prototype is only 10 cm2, the system's resolution is less than lOps, the measurement accuracy is better than 30ps, the measurement range is more than 20,000 seconds, and its measurement results are highly reliable.