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ADC and DAC

Embedded Systems Hardware Embedded Systems Hardware Interface Signal
Author
swang
Table of Contents
Basics in Embedded Systems - This article is part of a series.
Part 2: This Article

Embedded System is a kind of computer. The only way they understand about this world is about 1 and 0. Thus, we need a method to dealing with real-world signal with converting analog signal to digital signal and vise versa. Thus, Analog to Digital Converter and Digital to Analog Converter play an important role in embedded systems.

ADC
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Embedded systems use ADCs to read analog inputs from sensors, including temperature, light, sound, and pressure. The way to convert signal from analog to digital is sampling.

2 Key specifications about sampling
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  • resolution: The number of bits used to represent each sample. A higher resolution allows for more precise measurements. For example, a 12-bit ADC can represent 4096 distinct values, while an 8-bit ADC can represent 256. The term “8-bit music”/“16-bit music” is a kind of description about sample resolution.

  • rate: The rate at which the ADC samples the analog signal, typically measured in samples per second. Higher sampling rates can capture fast-changing signals but may generate more data to process.

DAC
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The embedded systems usually use DAC to output continuous analog signal for controlling devices, such as motor, audio device.

2 Key specifications about settling
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  • resolution: Like ADCs, DAC resolution defines the number of distinct analog values that can be produced. A higher resolution provides finer control over the output signal.
  • settling time: This is the time the DAC takes to stabilize at a new output level after a change. Faster settling times are better for applications requiring rapid adjustments.

Hardware Configuration
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Usually followed by a Op Amp to reduce the output impedance.

Basics in Embedded Systems - This article is part of a series.
Part 2: This Article

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Embedded Systems Hardware Embedded Systems Hardware Interface