Thermometer code to binary code circuit for time-to-digital converter

Abstract

The invention discloses a circuit for converting a thermometer code into a binary code circuit for a time-to-digital converter. The circuit comprises: a LUT screening circuit and an RAM storage circuit, the thermometer code is used as an input signal, which is accessed to the LUT screening circuit, an LUT unit in the screening circuit performs negation on upper 5 bits of the input signal, adds a negation result to the lowest bit of the input signal to obtain an output signal, and accesses the output signal to a reading enable end of the RAM storage circuit as a control signal; and when the reading enable end is pulled up, the binary code in the corresponding RAM storage circuit is read out at the next clock rising edge, so that the conversion of the thermometer code into the binary code isrealized. The circuit disclosed by the invention solves the bubbling problem existing in a decoding process of the time-to-digital converter based on FPGA, and improves the overall performance of theFPGA type time-to-digital converter.

Description

technical field [0001] The invention relates to the field of integrated circuit measurement, in particular to a decoding circuit used in an FPGA-based time-to-digital converter to convert thermometer codes into binary codes. Background technique [0002] Time interval measurement technology is of great significance to national economy and national defense industry construction. Accurate time interval measurement technology, especially picosecond (1ps=10 12 s) magnitude of technology is more important. Whether it is in theoretical research fields such as molecular biology, nuclear physics detection, or astronomical observation, or in engineering practice fields such as laser ranging, high-precision positioning, and food and drug safety monitoring, it has very important applications. [0003] At present, the most widely used high-precision time interval measurement technology is time-to-digital converter (TDC) technology, and its most important technical index is measurement ...

AI Technical Summary

Problems solved by technology

The thermometer code-to-binary code circuit described in this document can better filter the "bubbling" code segment of the thermometer code, but its decoding algorithm is complex, the utilization rate of FPGA resources is not high, and the decoding time is long

At the same time, the timing characteristics of the decoder described in this document are poor, and the pipeline structure can eliminate the timing problem caused by too much delay in the logic path, which takes up more flip-flop resources

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