Basic concepts of 1 and DAC
DAC is a digital-to-analog converter (English: Digital to analog converter, abbreviated as DAC), which is a device that converts digital signals into analog signals (in the form of current, voltage or charge).
2. Audio signal in 2.DAC
Sound first appeared in the form of analog waveform. The recording, copying and playback of analog audio have serious defects-all analog recording carriers have noise floor, and every time they are played, copied and edited, new noise and new distortion will be introduced.
The audio code formed by sampling, quantization and coding can ensure high signal-to-noise ratio and low distortion, and its noise mainly comes from the process of analog audio digitization. But digital audio can't be played directly, so it needs to be replaced by analog signals.
At present, digital audio signals can be converted into analog audio signals through DAC chips (modules), including digital telephones, digital televisions, intelligent influences, computers and so on. , using DAC to complete related functions.
Extended data
At present, most DACs consist of resistor arrays and n current switches (or voltage switches). According to the digital input value, the switch is switched to generate a current (or voltage) proportional to the input, and a constant current source is added to some DACs to improve the accuracy. The main technical indicators are as follows:
1) resolution refers to the ratio of the minimum analog output (only the lowest bit of the corresponding digital quantity is' 1') to the maximum quantity (all significant bits of the corresponding digital quantity are' 1').
2) SettingTime is the time required to convert a digital quantity into a stable analog signal, which can also be considered as conversion time or response speed. Generally, the settling time of current output DA is short, while the settling time of voltage output DA is long.
Other indicators include linearity, conversion accuracy, temperature coefficient/drift.
At present, DAC is gradually moving towards integration.
References:
D/A converter _ Baidu Encyclopedia