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Noise observed when 150 Hz test tone data is captured using EVAL-ADAS1000 EVM.

Category: Hardware
Product Number: EVAL-ADAS1000


We are trying to capture the Test tone data using EVAL-ADAS1000 EVM. The 1Hz, 10Hz test tone waveforms are fine. However, 150Hz test tone waveform is not proper. 

In Frame control register We are using a setting of Every 4th frame is output. Is it the issue because our sampling rate is 500 Hz...? Please clarify.


  • Hi Subbash,

    Since you have 150Hz test tone configured and you are doing 500Hz sampling rate but decimating the data by 4, you effectively have 125Hz sampling rate which is lower that your 150Hz sine wave. Ideally, your sampling rate should be twice the frequency of you input signal. You can try outputting every frame.

    You might also need to check your FILTCTL to make sure that LPF is set to 250Hz to make sure that the 150Hz sine wave can pass through, 

    The ADAS1000 datasheet has details on how to configure and measure 150Hz testone in ADAS1000. 

    ADAS1000/ADAS1000-1/ADAS1000-2 (Rev. C) (



  • Dear Mark, 

    Actually, We are Capturing data at 2kHz and decimating by 4. So the effective sampling frequency is 500Hz. The sampling frequency is 3 time the input signal (150Hz sine wave).

    at 2kHz sampling frequency, without decimation, the sine wave looks to be fine.

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