D/A converter (also known as digital-to-analog converter, referred to as DAC) is a device that converts discrete signals in the form of binary digital quantities into analog quantities based on a standard quantity (or reference quantity). The function of a converter is to convert digital quantities into analog devices.
A/D converter (also called analog-to-digital converter, or ADC for short) refers to a circuit that converts analog signals into digital signals. The function of A/D conversion is to convert analog quantities that are continuous in time and continuous in amplitude into digital signals that are discrete in time and discrete in amplitude.
A/D conversion generally goes through four processes: sampling, holding, quantization and encoding. In actual circuits, some of these processes are combined. For example, sampling and holding, quantization and encoding are often implemented simultaneously during the conversion process.
Extended information:
Analog-to-digital conversion methods can be divided into two categories: direct method and indirect method based on the conversion principle:
1. Direct method It directly converts voltage into digital quantity.
It uses a set of reference voltages output by the digital-analog network to repeatedly compare it with the measured voltage bit by bit starting from the high position until the two reach or are close to balance. The direct bit-by-bit comparison converter is a high-speed digital-to-analog conversion circuit with high conversion accuracy, but its ability to suppress interference is poor. Methods to improve the performance of data amplifiers are often used to compensate. It is most commonly used in computer interface circuits.
2. The indirect method does not directly convert the voltage into a number, but first converts it into an intermediate quantity, and then converts the intermediate quantity into a number.
There are two commonly used methods: voltage-time interval (V/T) type and voltage-frequency (V/F) type. Among them, the double slope method (also called double integration method) in the voltage-time interval type ) is more commonly used.
Baidu Encyclopedia-Analog-to-digital converter
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