Chronometer time automatic measurement circuit based on TDC-GP 21 and method

Abstract

The invention provides a chronometer time automatic measurement circuit based on TDC-GP 21 and a method, and solves the problems that due to adopting a double-bevel interpolation technology to measure a chronometer time interval in the prior art, the space is large, the cost is high, the power consumption is large, and a measuring result has a zero-point error and a non-linearity error. The chronometer time automatic measurement circuit based on the TDC-GP 21 comprises a first trigger, a delayer, a second trigger, a multiplexer, a third trigger, a fourth trigger, a TDC-GP 21 chip and an FPGA (field programmable gate array) chip. The chronometer time automatic measurement circuit based on the TDC-GP 21 provided by the invention has the advantages that the structure is simple, the cost is low, the power consumption is small, the measuring accuracy is high, the linearity is good, and the measured time accuracy can achieve 45 ps; and the chronometer time automatic measurement circuit has an automatic calibration function and can automatically compensate errors caused by the variation of voltage and temperature, the measuring speed is rapid, and the replacement rate of a waveform of a digital type wavetable is observably improved.

Description

technical field [0001] The invention relates to the technical field of testing, in particular to a circuit and method for accurately measuring the time interval (Δt) between a trigger point and a sampling point applied in a hand-held digital oscilloscope. Background technique [0002] Traditional oscilloscopes often use double-slope interpolation technology to achieve precise time measurement. Double-slope interpolation technology uses capacitor charging and discharging circuits to widen the tiny time interval to measure time. figure 1 Shown is a traditional double-slope interpolation circuit, which is a double-slope integrating circuit with fast discharge (falling slope) and slow charging (rising slope), because the charge and discharge of capacitor 101 are equal each time, that is, t 充 ×I 充 = t 放 ×I 放 , so the interpolation gain G=I 放 / I 充 = t 充 / t 放 , the expanded waveform is shaped by the comparator 102, and is added to the precision interpolation counter 103 as a...

AI Technical Summary

Problems solved by technology

[0004] The present invention proposes a precise time automatic measurement circuit based on TDC-GP21, which solves the problem of using double-slope interpolation technology to measure precise time intervals in the prior art, which has large space, high cost, and large power consumption, and there is a zero-point error in the measurement results. and non-linear errors, the temperature characteristics of the oscilloscope are very strict, and the measurement response speed of the circuit is slow during continuous measurement.

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