ADC and DAC

ADC and DAC

1. ADC(Analog to Digital Converter

   • Quantization
     • converts the dependent variable from continuous to discrete.
   • Sampling
     • converts the independent variable from continuous to discrete.
   • Quantization whitout Samplings
     • is used in switched capacitor filters
   • PROCESS
     • ANALOG INPUT
       • The first stage is the sample-and-hold
         • where the only information retained is the instantaneous value of the signal
           • when the periodic sampling take place
         • Second Stage, the ADC
           • Converts the voltage to the nearst integer number.
           • Result
             • in each sample in the digitized signal having an error of up to +-1/2 LSB
               • DIGITAL OUTPUT
     • Graphic

2. DAC( Digital to Analog Converter

   • is to pull the samples from memory
     • convert into an
       • IMPULSE TRAIN
         • is a continuous signal consisting of a series of impulses that match the original signal at the samplings instants
   • equivalent of the sample-and-hold used during ADC
   • Analog Filters for Data Conversion
     • shows a block diagram of a DSP system
       • DSP (Digital Signal Processor
       • INPUT SIGNAL
         • the input signal is processed with an electronic low-pass filter to remove all frequencies above the Nyquist frequency (one-half the sampling rate)
           • the digitized signal is passed through a digital-to-analog converter and another low-pass filter set to the Nyquist frequency.
             • an analog signal formed from frequencies between DC and 10 kHz will have exactly the same resolution as a digital signal sampled at 20 kHz.

3. Created by Oscar Valdelamar

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