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TIDA-01606: Noisy signal from ADC

Part Number: TIDA-01606

Hi Team,

We would like to ask your help regarding the customer's inquiry below.

I am using an f28379d control card to control the TIDA-010039, three stage, three phase SiC AC / DC converter. I program the MCU via Matlab Simulink and it works fine for me but I am having trouble reading the ADC's input voltage via USB. When I display the measured voltages on the PC via a USB connection, I have a noisy signal with around 100 bits, which means around 80 mV noisy signal (3.3 V reference). If I measure the voltage directly at the input pin of the control card or alternatively behind the integrated noise filter, I cannot see any noise. It's close to a perfect signal.

In my understanding the problem is located on the MCU. But if i use the control Cards docking station i there is no noisy signal to measure. It is perfectly what it should be. (Furthermore i choose a very long Acquisition Window for the ADC Measurement.. this should not be the problem)

In summary: The combination of TIDA-010039, F28379D Control Card and the USB connection to the laptop creates a noisy signal that I cannot explain. Can you help me please?

I have two pictures for a better explanation. The control card is integrated in the TIDA-010039. But as i explained, the voltage that i measured directly on the control card seems to be clean

Regards,

Danilo

  • Danilo, Sometimes you can add a small capacitor on the control card to help ADC see less noise. 

     

    When you test with matlab on the control card the signal is clean on the MATLAB plot?

  • Hi Manish,

    Thank you for your response. According to the customer,

    i will test adding a small low pass filter directly on the control card. To answer your question - the signal of the Matlab plot is clean when the control card is not inside the TIDA-010039. I tested this several times in the docking station.
    In docking station clean, in TIDA not clean. - Noise comes from the TIDA Equipment. I will research this.

    In further mesurements i also noticed, that the time span of my oscilloscop was in 10ms per division (see the oscilloscop photo). That means, i cant see high frequency noise on the input signal.
    That means, my first asumings are not correct.
    I will give you an update if it is possible for me to add a low pass filter to the control card.

    Regards,

    Danilo

  • Hi Manish,

    Adding small capacitor on the control card resolved the issue. Thank you very much for your suggestion.

    Regards,

    Danilo