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Analog-to-digital Conversion and Digital-to-analog Conversion (with DSP). ES-3. 8R. V 1. V OUT. 4R. V 2. 2R. V 4. R. V 8. 8R. A very simple (…too simple!) Digital-to-analog converter. A simple Analog-to-digital converter. Analog Input. +. -. scitec.uwichill.edu.bb.
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Analog-to-digital ConversionandDigital-to-analog Conversion(with DSP) ES-3
8R V1 VOUT 4R V2 2R V4 R V8 8R A very simple (…too simple!)Digital-to-analog converter
A simpleAnalog-to-digital converter Analog Input + - scitec.uwichill.edu.bb
A simpleAnalog-to-digital converter Analog Input 3.5v + high low - 0v 3v 2v 3v 4v 1v 0 0 0 0 0 1 0 0 0 0 0 0 0 0 1 1 0 0 0 0 0 1 0 0 0 0 0 0 0 0 1 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 0 1 Improve accuracy: scale the DAC scitec.uwichill.edu.bb
Nyquist Sampling RateThe sampling of data must be at least twice the rate as the maximum frequency of the analog signal: fs>2fmax V(t) Time, t Use a low pass filter with fc = fmax to remove harmonics sine
Aliasing Nyquist Sampling RateThe sampling of data must be at least twice the rate as the maximum frequency of the analog signal : fs>2fmax V(t) Time, t
Find the average of N points Digital FilteringRemoving Noise and Interference from a Digital Signal
sine + noise filtered noise FFT of a noisy sine wave and its digitally filtered signal
Vin(n-12) Vin(n) Simple Notch Filterto remove 60 Hz interference Vin(n) fS = 1440 samples per second 60 Hz sine t (s) 1/60 s Vout(n) = Vin(n) + Vin(n - fs / 2fnotch) = Vin(n)+Vin(n-12) This adds the sample that is 1800 out of phase at 60 Hz
Matlab demo es3_60Hz.m