Method for simulating DAC function based on PWM, digital-to-analog conversion circuit and storage medium

Abstract

The invention discloses a method for simulating a DAC function based on PWM, a digital-to-analog conversion circuit and a storage medium. The method for simulating the DAC function based on PWM comprises the following steps: obtaining the digit W1 of a first PWM signal and the digit W2 of a second PWM signal used for forming the first PWM signal; determining the number A of second PWM signals required for forming a first PWM signal according to the digit W1 and the digit W2; acquiring a signal parameter H1 of the first PWM signal; determining a signal parameter H2 of the second PWM signal according to the signal parameter H1; and outputting a first PWM signal composed of A continuous second PWM signals according to the digit W2 and the signal parameter H2. According to the method for simulating the DAC function based on the PWM, the harmonic frequency can be improved, so that the cut-off frequency of the low-pass filter is improved, the phase lag of DAC output is reduced, the time constant of the RC filter is reduced, the response speed is improved, and the requirement of a system for the response speed is met.

Description

technical field [0001] The invention relates to the technical field of electronic applications, in particular to a method for simulating a DAC function based on PWM, a digital-to-analog conversion circuit and a storage medium. Background technique [0002] In the field of electronic application technology, MCU and DAC are widely used. However, many MCUs do not have integrated DAC functions or the number of DACs integrated inside MCUs is relatively small. In systems that require multi-channel DAC functions, the DAC function resources of single-chip microcomputers are far from enough, and the cost of externally expanding DAC chips increases a lot. At present, in practical circuit applications, almost all MCUs provide timer or PWM output functions; the classic PWM analog DAC in practical circuits uses PWM+RC filtering to realize the DAC function. [0003] However, this implementation method requires a low-pass filter with a very low cutoff frequency, and the lag of the DAC out...

AI Technical Summary

Problems solved by technology

[0003] However, this implementation method requires a low-pass filter with a very low cut-off frequency, and the lag of the DAC output will also increase, resulting in longer response time and slower response speed

The traditional solution is to reduce the counting pulse width of the single-chip microcomputer, that is, to increase the operating frequency of the single-chip microcomputer, but in practice, this solution is limited by the clock of the single-chip microcomputer and the switching characteristics of the PWM follow-up circuit

Corresponding to systems that require microsecond or even higher-level response speed, the typical PWM+RC filter output DAC response speed of the actual circuit cannot meet the system requirements

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