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ADC12DL065: Varying the sampling rate

Houari Cobas Gomez
Prodigy 80 points
Part Number: ADC12DL065
Other Parts Discussed in Thread: ADS7808, ADC12010, ADS7142

Hello, i would like to know how could i vary the ADC12DL065 sampling rate. I´m working in a design where i will need to perform data adquisition at differents sampling rates depending on the system conditions. My system need sampling rates that can vary from 0.1 s down to 0.1 us. 

How can i do this with the ADC12DL065? Is it´s sampling rate fixed to 65 MSPS?

Thanks 

  • 0
    TI__Genius 12780 points

    Hello,

    The minimum sampling rate for the ADC12DL065 is 15 MSPS, according to page 10 of the datasheet. I am checking with my colleagues to see if we have an ADC that can support sampling rates from 10 Hz to 10 MHz.

    Best Regards,

    Dan

  • 0 in reply to dBrock
    Prodigy 80 points

    Great, I will be waiting for your sugestion. Also, I would appreciate any sugestion in order to do a system like this with sampling rates from 10 Hz to 10 MHz.

    Thanks

  • 0 in reply to Houari Cobas Gomez
    TI__Genius 12780 points

    Hello,

    We do not have an ADC that can support this range of sampling rates. If you are able to provide more information (required bit resolution, input signal frequency, output data interface, application), I may be able to help more. Is the input frequency remaining the same? What is driving the need for changing the sampling rate?

    We have many ADCs that can sample at 10 MSPS. If you need 12 bits, you can start by looking at the ADC12010 which can sample from 100 kHz to 10 MSPS. You could have a mux that switches from the high speed adc to the low speed adc (like the ADS7808).

    Other than that, you may be able to sample at the highest speed and digitally decimate the data to the data rate that you require.

    Best Regards,

    Dan

  • 0 in reply to dBrock
    Prodigy 80 points

    Hello Dan,

    Well, I´m working in designing a system that one of its functions is to perform a frequency sweep (current sinusoidal waveform) from 0.1 Hz to 100 kHz (higher frequency would be better, but if i get 100 kHz it will be ok). In this system i will have to measure the current and voltage in order to calculate the impedance for each frequency point. 

    I want to do a decadic frequency sweep.

    I´m looking for 12 bit converter or higher. The current values are low, so i will have to do some signal conditioning.

    At this point i need to convert to digital the current and voltage signals with that frequency sweep. I was looking for a ADC with two ADC so i could simultaneously adquire both signals.

    I have to see how to change the DAC sampling rate, so i can get 100 samples for each signal period.

    Beste regards,

    Houari

  • 0 in reply to Houari Cobas Gomez
    TI__Genius 12780 points

    Hi Houari,

    If you are willing to sample from 0.1 Hz to 100 kHz, I think that this can be done with the ADS7142 (12 bit, 2 channel (single-ended input). I will check again with my colleagues to make sure this is the best part for your application.

    Best Regards,

    Dan

  • 0 in reply to dBrock
    Prodigy 80 points

    Dan, for getting a full period representation with 100 samples, with a 100 kHz frequency signal i would require a samplin period of 0.1 us or a sampling frequency of 10 MHz.

    That´s why i was looking that sampling rate.

    Best regards,

    Houari

  • 0 in reply to Houari Cobas Gomez
    TI__Genius 12780 points

    Hi Houari,

    Ok, I think I had misunderstood that you will be sampling up to 100 kHz input signal. In this case where 100 samples are required, I don't think we can support your application with a single ADC solution.

    Best Regards,

    Dan