Input and output circuit with low pass filtering function

Abstract

The invention discloses an input and output circuit with a low pass filtering function. The input and output circuit comprises an output module, an ESD protection module, a low pass filtering module and an input module; the output module is connected with output of a chip core and a PAD, and used to output a driving current of a milliampere level; the ESD protection module is connected between the PAD and the low pass filtering module to provide electrostatic protection for the PAD; the low pass filtering module is connected between the ESD protection module and the input module, and used to filter high frequency noises and pass low frequency signals; and one end of the input module is connected to the low pass filtering module, the other end of the input module is connected with the chip core, and the input module is used to convert input signals into analog/digital signals that satisfy requirements of subsequent circuits. According to the invention, the input and output circuit with the low pass filtering function can be realized, high frequency interference higher than the working frequency of signals is isolated effectively, the success rate of signal transmission is improved, and the electromagnetic compatibility of a chip is ensured.

Description

technical field [0001] The invention relates to an input and output circuit, in particular to an input and output circuit with low-pass filtering function. Background technique [0002] There is no low-pass filter module in the input and output circuits of the existing integrated circuit chip, and special discrete devices are mainly used on the PCB to realize the isolation of EMI interference. Chinese utility model patent CN204441430U provides a low-pass filtering structure and low-pass filter, such as figure 1 As shown, the low-pass filter is a discrete device, and its structure includes at least two low-pass filter layers (low-pass filter layer 10 and low-pass filter layer 20), at least two layers of low-pass filter layers are arranged at intervals, wherein at least two One low-pass filter layer in the low-pass filter layer includes a plurality of circular conductive geometric structures or a plurality of polygonal ring conductive geometric structures, and the other low-p...

AI Technical Summary

Problems solved by technology

[0003] With the reduction of the package size of integrated circuit chips, the EMI interference between lines becomes more serious. If other signals between adjacent pins introduce a certain intensity of electromagnetic interference, it may cause the input signal to have spurious noise. This phenomenon It is more serious in the case of low-voltage applications, and only using low-pass filter devices on the PCB cannot effectively avoid this problem

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