FPGA (field programmable gate array)-based time-digital converter

Abstract

The invention discloses a FPGA (field programmable gate array) chip-based TDC (time-digital converter). The TDC comprises a pulse signal generator, a multi-tap signal delay chain, a trigger array, two parallel signal change edge search circuits, a rising edge 'one-hot' coding circuit, a falling edge 'one-hot' coding circuit, a calibration circuit and a conversion result output circuit, wherein the rising edge 'one-hot' coding circuit is parallel to the falling edge 'one-hot' coding circuit; the pulse signal generator is used for generating a negative pulse and feeding the negative pulse into the signal delay chain; the trigger array is used for latching states of all taps; after the taps are resorted, the states of the taps are transmitted to the signal change edge search circuits to search a rising edge and a falling edge of the negative pulse respectively, and corresponding 'one-hot' codes are generated. The TDC can remove 0 delay units on the delay chain to the maximum extent, reduce 'bubbling' phenomena in latch-state thermometer codes and enable performance indexes in three aspects of measurement precision, measurement dead time and resource occupancy to be reasonably balanced so as to realize a high-performance measurement system of the TDC.

Description

technical field [0001] The invention belongs to the field of digital measurement of time, in particular to an FPGA-based time-to-digital converter. Background technique [0002] Time measurement refers to measuring the moment when an event occurs, or measuring the time interval between two events. Time measurement technology has important applications in many fields, such as high-energy physics experiment research, nuclear medical imaging, military and civilian radar, and laser ranging and other fields require high-precision time measurement technology. A time-to-digital converter (TDC: Time-Digital-Convertor) is a functional device that converts time into digital quantities to record the moment when an event occurs. For the measurement of the time interval between two events, generally two TDCs can be used to measure the occurrence moments of the two events respectively, and the difference between the two occurrence moments is the time interval between the two events. At ...

AI Technical Summary

Problems solved by technology

However, the current TDC implementation scheme cannot achieve good indicators in the three aspects of improving measurement accuracy, reducing measurement dead time, and reducing resource usage.

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