Digital Circuit Noise Filter and Digital Filtering Method

Abstract

The invention discloses a digital circuit filter, comprising: an independent burr filtering module for receiving an input signal and filtering out the independent burrs in the signal; an associated burr filtering module whose signal input terminal is connected to the independent burr filtering module Connected to the output end of the , used to receive the input signal that has been filtered out of independent burrs, and filter the burrs associated with the signal waveform; the burrs associated with the signal waveform include burrs that appear before the signal waveform and burrs that appear after the signal waveform The distance between the burr associated with the signal waveform and the signal waveform does not exceed the pulse width of the burr; the independent burr filtering module and the associated burr filtering module distinguish and filter out burrs in the time direction. A corresponding digital filtering method is also disclosed. The above-mentioned digital filter and digital filtering method adopt the method of distinguishing and filtering burrs in the time direction, which can eliminate pulse noise with large amplitude and avoid clock or signal errors.

Description

technical field

[0001] The invention relates to the technical field of digital circuits, in particular to a digital circuit noise filter and a digital filtering method. Background technique

[0002] Chips are often subject to external disturbances in the system, such as electrostatic discharge, momentary power switch jumps, or momentary signal jitter caused by lightning. The above interference will introduce short-term but large-amplitude noise pulses, the effect of which is similar to glitches for digital circuits, which may cause clock pulse errors or signal transmission errors.

[0003] For the glitches caused by crosstalk, the general approach is to use a Schmitt trigger, so that the amplitude of the input signal will not cause the output signal to jitter within a certain range. The input and output curves of the Schmitt trigger are as follows figure 1 shown. When the input is less than -T and increases from -T to T, the output is -M; when the input is greater than T ...

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