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Original question:

DAC1282: DC Output Generation

DAC1282: DAC1282IPWR

Jonghu Ju
Prodigy 10 points
Part Number: DAC1282

Tool/software:

I have used DAC1282IPWR for 24bit DC mode  operaion.

The initialization procedure is as follows:

1. power on

2. After 1,000,000 clocks, reset signal changed to high.

3. Setting SPI register value:

      address 0  -> 0x01 

       address 1 -> 0xFF

       address 2 -> 0x00

        address 3 -> 0xFF

       address 4 -> 0x00

       address 5 -> 0x00

       address 6 -> 0x80

I have very noise pattern at VOUTP pin as follows 

When I set address 0 -> 0x00(Sine mode) , I have very low noise normal sine wave pattern.

Please recommend me,for removing below noise pattern at DC mode

  • 0
    TI__Mastermind 46580 points

    Hello Jonghu Ju,

    Welcome to the TI E2E community!

    The DAC1282 has about 200mVpp of noise with a fundamental frequency of about 8kHz.  This is normal behavior for the ADC.  It is intended to be used with a high precision delta-sigma ADC with a digital filter bandwidth of about 420Hz.

    If you want to use this DAC for general purpose applications, then you will need to add an analog output filter.  First, make sure to include the output capacitors, as these provide a first stage filter using 1nF C0G ceramic capacitors.

    You can add an additional differential output filter as shown below to further reduce the DAC output noise.

    Regards,
    Keith Nicholas
    Precision ADC Applications