基于差分PWM的低成本音频输出方案研究与设计

打开文本图片集

中图分类号：TN912.3 文献标识码：A 文章编号：2096-4706（2025）17-0012-06

Abstract：Alow-cost audio output scheme based on diferential PWM technology instead of traditional Codec chip is proposed.By analyzing the basic principle of sound and the application of PWMtechnology in analog signal generation， a diferentialaudiooutputcircuit basedonsecond-orderRClow-passfiltering isdesigned.Experiments show thatthescheme can effectively filter out high-frequency carrier noise while ensuring the normal output of audio signals below 20kHz ，and has good anti-interference ability.The test results show that under the design parameters with acut-off frequency of 2kHz the audio distortion of the system is less than 1% ，and Signal-to-NoiseRatio is higher than 80dB ，which can effectively replace the traditional Codec scheme and reduce the system cost byabout 30% .This design is suitable for consumer electronics products that are not demanding on sound quality but are cost-sensitive.

Keywords： differential PWM; audio output; low-cost; low-pass filtering; embedded system

0 引言

在音频方案中，通常使用 I2S 接口连接音频编解码芯片，该方案的缺点是占用硬件资源多且成本较高。（剩余8374字）