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ADC - 24 bits with frequency about 300 kHz

Hello,

I'm looking for a ADC with about 300 kHz (24 bits) and if possible wit the adjustable sampling rate. Do you know if there is component ? Thanks for your helps. 

Ragards.   



24 bits - 300 kHz - Fe ajustable
[edited by: 206_RC at 3:38 PM (GMT -5) on 17 Jan 2022]
  • Hi, 

    If you can provide more details about your application and other requirements (i.e. no. of channels, input type, supply ranges, etc.) then we can help narrow down the selection. May I confirm what do you mean by 300kHz is that the maximum sampling rate you need per channel? or the overall throughput? or is that the max analog input BW you need?

    For the mean time you can try to check these parts and see if any of these suits your application.

    AD4134 Datasheet and Product Info | Analog Devices

    AD7768-1 Datasheet and Product Info | Analog Devices

    AD7760 Datasheet and Product Info | Analog Devices

    Thanks,

    Jellenie

  • Hi, thank you for your answer. My developpement is about the acquisition the sounds at the bottom of the sea. The measuring range is : 50dB to 100dB (ref 1µpA) and the corresponding frequency range is : 100 Hz to 15kHz. So I must take this measure via Hydrophone with a ADC in 24 bits format that why I'm looking for a ADC with Fe(Sampling frequency) about 300 kHz with the possibility of varying this sampling frequency (it depends on where we are). Also we need to have HPF to cut low frequencies and similarly we would like to have de possibility to adjust this HPF. I'll read the component datasheet references and I will get back to you. Regards

           

  • Hi,

    After reading the component datasheets, probably this device 'AD7768-1' can be fit my application. In first, can you answer me 2 questions please :

    -  The maximum sampling frequency of the component is 256kHz right ?  

    -  Can this sampling frequency be modified by programming or by external switches?
    Thank you for your feedback.

    Regards.

  • Hi, 

    The sampling frequency is up to 1024kSPS with Fast sinc5 filter. It can be programmable via SPI by writing to Digital_Filter register or it can also be program via Pin control mode as shown in Table 22. 

    Thanks,

    Jellenie

  • Hi, 

    Thank you for your answer. After Table 22 below :

    I don't need such a high sample rate. With a sampling frequency around 120 kHz that would suit me perfectly. On the other hand, what will be the adjustable sampling frequency range between 1 kHz and 120 kHz ? Do yo have a component reference with a maximum sampling frequency around 120 kHz and 8 adjustable ranges of sampling frequency.  

    In your engine search :

    If I select a number bit of resolution 24 and frequency sampling min and max I have these characteristics. I don't the possibilty to select if a component is adjustable (fe) ?       

     

    Thank for your helps.

    Regards

  • Hi, 

    The AD7768-1 can still work with lower sampling rate as per table 22. And operating at lower ODR can also mean better noise performance. 

    With the table you have shown, most of our Sigma Delta ADCs have flexible filter and ODR options. There are also SAR who have some flexibility but with limited averaging options. Sigma Delta have more flexibilities in terms of adjusting the sampling rate or ODR.  

    Thanks,

    Jellenie

  • Hi, 

    You say : 'most of our Sigma Delta ADCs have flexible filter and ODR options' Yes I can see but I need to have several range of settings in the desired frequency range. For example 

    We need to have this options for our applications. I find this component :

    But I don't know how many possibility for the sampling frequency ? Thank for your helps

    Regards 

  • Hi, 

    I see I think that is quite difficult to achieve using a single ADC. Most of the ADCs have decimation or averaging in a factor of 2, 8, 16, 32, etc. The AD7764 have only few options of decimation. The narrowband ADCs such as AD717x (e.g. AD7175-2) for example offers more options and flexibility in terms of output data rate however, it operates at a much slower speed than the wideband. I think the AD4134 also offers more ODR options (not exactly what you need) but is quite closer. I think having that you only need 1 channel, using multiple channels (measuring simultaneously the same inputs) can also allow you achieve your target sampling rate. 

    Thanks,

    Jellenie

  • Have you looked at the LTC2368-24. This is a 24-bit SAR ADC that can sample from 1SPS to 1MSPS.