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Topic: Quantization noise on DUE DAC (Read 1 time) previous topic - next topic

wowden

Oct 24, 2017, 05:21 pm Last Edit: Oct 24, 2017, 05:56 pm by wowden
I am trying to make use of the DACs on the DUE for a project, but they seem to have quite abit of what appears to be Quantization noise. After being written to, the DACs seem fluctuate randomly in discrete steps at the 1-3 bit level @ 10 kHz(see attached picture, both DACs LP filtered at 300 kHz). Is this to be expected? Does anyone know why this happens?

Code: [Select]

void setup() { 
    analogWriteResolution(12);
}

void loop() {
analogWrite(DAC1, 1000);
analogWrite(DAC0, 1000);
while(true){};
}


edit: Seems like I am not the first...http://forum.arduino.cc/index.php?topic=194694.0

ard_newbie


I have not read anything about this issue, but IMO for a serious leverage of the DACs, one should use DACC registers programming rather than the analogWrite() function.  E.g. DACC_MR_REFRESH() 8 bits in DACC->DACC_MR should not be at 0, the minimum should be 1.

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