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).

The abbreviation of power amplifier generally refers to the most basic equipment in audio system, commonly known as "amplifier". Its task is to amplify the weak electric signal from the signal source (or the mixer in the professional sound system) and drive the speaker to make sound. It can also refer to other devices used for power amplification.

Composition and characteristics:

DAC is mainly composed of digital register, analog electronic switch, bit weight network, summing operational amplifier and reference voltage source (or constant current source). The analog electronic switch of the corresponding bit is controlled by each bit of the digital quantity stored in the digital register, so that the bit numbered 1 generates a current value proportional to its bit weight on the bit weight network, which is then added by the operational amplifier and converted into a voltage value.

According to different bit weight networks, different types of DACs can be formed, such as weighted resistance network DAC, R–2R inverted T-shaped resistance network DAC and single-valued current source network DAC. The conversion accuracy of weighted resistor network DAC depends on the reference voltage VREF and the accuracy of analog electronic switch, operational amplifier and weighted resistor values.