Time digital converter and time measurement method

Abstract

The invention provides a time digital converter and a time measurement method. The time digital converter comprises a disorder signal generating unit, which is used for generating a plurality of disorder clock signals; a sampling unit, which is used for receiving a plurality of disorder clock signals and input signals to be tested, sampling multiple disorder clock signals by using the input signal to be tested, and outputting corresponding actual sampling result; a decoding unit, which is used for receiving the actual sampling result, and confirming the time difference between a specific edge of the input signal to be tested and the specific edge of selected clock signal in multiple disorder clock signals according to the actual sampling result and the time sequence information related to the time sequences of multiple disorder clock signals, so as to acquire the fine time result of the input signal to be tested; a rough time counting unit, which is used for receiving the selected clock signal and the input signal to be tested, and counting the input signal to be tested by using the selected clock signal as the counting signal, so as to acquire the rough time result of the input signal to be tested. The TDC has high time resolution rate.

Description

technical field [0001] The invention relates to the field of circuits, in particular to a time-to-digital converter and a time measurement method. Background technique [0002] High-precision time-to-digital converter (Time-to-Digital Converters, TDC) technology is widely used in time-frequency measurement, satellite navigation, radar positioning, laser ranging, medical treatment, nuclear physics and particle physics detection and other fields. The time resolution of TDC largely affects the advanced degree of these fields. Taking the medical whole-body positron emission tomography (PET) system as an example, compared with the traditional PET without TDC, PET based on Time of Flight (TOF) technology with a time resolution of 600ps (TOF-PET for short) The signal-to-noise ratio of the image can be increased by 2.1 times, and the image signal-to-noise ratio of TOF-PET with a temporal resolution of 100ps can be increased by 5.2 times. [0003] A method combining coarse time mea...

AI Technical Summary

Problems solved by technology

If the phase relationship of the delayed signal is disturbed, the accuracy of the time measurement will be affected

In addition, because there are some addition and carry chains with a large BIN width (about 100ps) inside the FPGA, the time resolution of the time interpolation method is limited.

At present, most of them adopt the method of customized wave (Wave Union) to eliminate the influence of these large BIN widths, but it consumes more internal FPGA resources, and the "bubble" phenomenon caused by the metastable phenomenon of registers is difficult to solve

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