Group delay test method and device thereof

Abstract

The invention provides a group delay method to test the group delay Tgd. It includes the steps: (A) inputting a known period-T analog single-frequency signal to one input end of the tested device; (B) extracting the input single frequency and the output delayed one and converting them into a first digital signal and a second one, respectively; (C) comparing phase difference of the first and second signals; (D) converting the comparing result into a current I in direct proportion to the phase difference; (E) making the current I flow through a average circuit with a value-known resistance R and obtaining a voltage differenceªñV; and (F) according to known T, I, R andªñV, finding Tgd.

Description

technical field [0001] The invention relates to a group delay testing method and device, in particular to a testing method and device for testing the group delay of the tested device by sending a single frequency signal into the tested device. Background technique [0002] Generally, when an electronic device circuit transmits a data signal, the delay (ie, the time spent) encountered by the signal passing through the electronic device circuit is called a group delay. Group delay has a non-negligible impact on many electronic devices. For example, in data storage systems, if the group delay of internal electronic devices cannot be fully grasped, the relative timing accuracy of data reproduction cannot be guaranteed. This situation will cause Data decoding error. In addition, for a digital communication system, if the group delay is not properly dealt with, it will cause nonlinear distortion of the signal, resulting in an increase in the decoding error rate of the digital sig...

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Problems solved by technology

[0009] 4 The aforementioned high-speed digitizers and high-resolution test instruments are very expensive, so a higher cost must be spent

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