Vehicle-mounted DVD (Digital Video Disk) navigation and video-audio device adopting purely digital audio processing

Abstract

The invention relates to a vehicle-mounted DVD (Digital Video Disk) navigation and video-audio device adopting purely digital audio processing. The device is characterized by being internally provided with an ARM (Advanced RISC Machine), a DSP (Digital Signal Processor) and a digital power amplification module, wherein a control end of the ARM is connected with the DSP; a PCM (Pulse-Code Modulation) output end of the DSP is connected with a PCM input end of the digital power amplification module; and a PWM (Pulse-Width Modulation) output end of the digital power amplification module is connected with a loudspeaker. The invention adopts the scheme of ARM+DVD+AudioDSP+DigitalAMP to realize a totally digital play function and has the advantages of small volume, light weight, high power, strong capacity of resisting disturbance, stable signal transmission, reduction of quantizing noise and distortion which are introduced by a traditional analog processing mode, realization of the restoration of high fidelity tone quality, and the like.

Description

technical field [0001] The invention relates to a car DVD navigation audio-visual device using pure digital audio processing. Background technique [0002] At present, the car DVD navigation audio-visual system on the market generally adopts the digital signal output by the DVD core. First, after D / A digital-to-analog conversion, the output analog signal is processed by sound effect, filtered, and then sent to the power amplifier to drive the speaker. output. Some directly use the D / A digital-to-analog conversion device integrated in the DVD core. The D / A digital-to-analog conversion process here will bring a large quantization error, and the use of the integrated D / A digital-to-analog converter in the DVD core will cause even greater quantization errors. At the same time, the transmission of analog signals is more susceptible to the interference of various electromagnetic radiation inside the machine, which brings a lot of noise and reduces the signal-to-noise ratio of t...

AI Technical Summary

Problems solved by technology

The D / A digital-to-analog conversion process here will bring about a large quantization error. Using the D / A digital-to-analog converter integrated in the DVD core will bring even greater quantization errors.

At the same time, the transmission of analog signals is more susceptible to the interference of various electromagnetic radiation inside the machine, which brings a lot of noise and reduces the signal-to-noise ratio of the system; in addition, the analog power amplifier has serious efficiency problems, generally at 30-50% about

Almost all analog power amplifiers use negative feedback circuits to ensure their electroacoustic indicators. In negative feedback circuits, in order to suppress parasitic oscillations, phase compensation circuits are used, which will cause transient intermodulation distortion.

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