What is the function of an A/D converter?
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The function of an A/D converter is to convert an analog signal, which is continuous in both time and amplitude, into a digital signal that is discrete in both time and amplitude. Introduction to A/D converters: The full name of an A/D converter is an analog-to-digital converter, which converts discrete signals in the form of binary digital quantities into analog quantities based on a standard (or reference) quantity. A/D converters can be divided into two major categories based on their conversion principles: direct method and indirect method. Direct method: Converts voltage directly into a digital quantity. A set of reference voltages output by a digital-to-analog network is used to compare with the measured voltage bit by bit from the highest bit until the two reach or approach equilibrium. The direct successive approximation converter is a high-speed digital-to-analog conversion circuit with high conversion accuracy, but its ability to suppress interference is poor. This is often compensated for by improving the performance of the data amplifier. It is most commonly used in computer interface circuits. Indirect method: Does not convert voltage directly into a digital quantity but first converts it into an intermediate quantity, which is then converted into a digital quantity. The commonly used types are voltage-time interval (V/T) and voltage-frequency (V/F), with the dual-slope method (also known as the dual-integration method) in the voltage-time interval type being more widely used.
The A/D converter acts as a translator between the analog and digital worlds. Environmental signals around us, such as temperature, sound, and light, are continuously varying analog signals. For digital devices like computers and microprocessors to understand this information, the A/D converter performs the crucial conversion. For instance, when a car's water temperature sensor detects temperature changes, it outputs a continuously varying voltage signal. The A/D converter then transforms this into a digital signal composed of 0s and 1s, enabling the vehicle's computer to recognize and display it on the dashboard. The process generally involves three steps: sampling to capture instantaneous values, quantization for level classification, and encoding into binary numbers. Thanks to it, our electronic devices can perceive changes in the real world.
