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ADC device selection

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Replies: 42

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Hello.

Please advise ADC device selection.

ADC resolution should be 16bit.

I want to convert 10 Mhz ~ 300Mhz analog frequency to ADC.

Please help by selecting ADC device.

Best Regards,
Jame, Shin

  • Jame, 

    Please specify the part number of the device you are using. 

    Yusuf

  • In reply to Yusuf%20Agoro:

    Hello Yusuf,

    I am not sure which part number to choose for the design I want.

    With MCU control, the ADC conversion value is first saved as a text file.

    Then, the text file is read from the PC program and the result value is displayed in graph form.

    The spec I think is below.

    -----------------------------------------------------------------

    ADC conversion time : (min) 1us       (max) 0.1us

    ADC Conversion rate : (min) 1Msps   (max) 10Msps

    ADC resolution bit   : (min) 12bit     (max) 16bit.

    ADC input channels : (min) 2 Ch     (max) 4Ch

    ADC Input Frequency : 10Mhz ~ 300 Mhz

    ADC input type : single-Ended

    MCU Interface : SPI

    -----------------------------------------------------------------

    There is a difficult part in selecting an ADC device from Ti for search.

    Q1> Which of the Precision Vs Highspeed ADC is suitable?

    Q2> I don't know what kind of architecture to choose.

            i.e) SAR, Delta-Sigma, Pipeline….,

    Q3> Please help me choose the ADC device suitable for my application.

    Best Regards,
    Jame, Shin

  • In reply to Jame shin:

    Shin:

    You will want a high speed ADC capable of supporting your analog input signal frequency.  There are many options and trade-offs with respect to performance, cost, and power consumption.  There are also different options depending on the digital interface requirements.  Based on your information above I will give you a few starting points to investigate for 16-bit resolution devices.

    JESD204B Interface

    • ADS54J69 - 16b, 500MSPS,1200MHz BW
    • ADS54J60 - 16b, 1000MSPS, 1200MHz BW
    • ADC16DX370 - 16b, 370MSPS, 800 MHz BW

    LVDS Interface

    • ADS42LB69 - 16b, 250MSPS, 900 MHz BW

    --RJH

  • In reply to RJ Hopper:

    Hello RJH,

    Thank you for the reply.

    From the starting point of 16bit ADC device selection, I am moving forward.

    I previously only used the ADC built into the Ti 32bit MCU, but I have a lot of trouble selecting a separate ADC device.

    Q1> How do I interface between  ADC device(JEDS204B Vs LVDS Parallel)  and  MCU?

    Q2> I would like to create a text file of the results of the ADC acquisition data with the thoughts I prepared for designing the GPR equipment.

            The reason is to make development design easy.

            Advise your thoughts and ideas.

    Q3> I am not free of cost on the ADC device you suggested.

           Reduce development specs by one step in cost.

           (Modify Spec)

            ---------------------------------------------------------------------

            ADC Input Frequency : 10 Mhz ~ 100 Mhz

            ADC input channels l : Up to 4Ch(min) ~  8Ch(max)

            ---------------------------------------------------------------------

          Would you please tell the starting point again in selecting ADC device?

    Q4> Why can't I use it as a design application with a Precision ADC device?

    Best Regards,
    Jame, Shin

  • In reply to Jame shin:

    Shin:  Please see below.  --RJH

    Q1> How do I interface between  ADC device(JEDS204B Vs LVDS Parallel)  and  MCU?

    RJH>> Not sure I can answer this.  It depends on the capabilities of the MCU and the digital interface options.  You mentioned before you used an ADC built in to the MCU.  My guess is that ADC must have been a lower sampling rate and lower performing option compared to the recommendations I provided.  Typically our high performance ADC interface to an FPGA that is capable of supporting the LVDS or JESD204B interface.  If your MCU if fixed, then you will need to work around its capabilities.

    Q2> I would like to create a text file of the results of the ADC acquisition data with the thoughts I prepared for designing the GPR equipment.

    RJH>> For prototyping or demo purposes, you can use the TI ADC with the TI capture card (used for evaluation).  The corresponding software, HSDC Pro Software, can export captured data to a file.

    Q3> I am not free of cost on the ADC device you suggested.

    RJH>>  16b and high speed together will set a price point.  You can downgrade the resolution to 14b and then some lower sampling rate options come into play.  These devices will be less expensive.

     - ADC3241   14b, 25 MSPS, 540 MHz BW, Serial LVDS interface

    Q4> Why can't I use it as a design application with a Precision ADC device?

    RJH>> You may be able to and your MCU interface may dictate a Precision ADC.  I targeted high speed converters given the nature of the application (radar signals) and the frequency up to 300 MHz.

  • In reply to RJ Hopper:

    Hello RJH,

    RJH_A> You may be able to and your MCU interface may dictate a Precision ADC. 

    I 'm change Precision ADC device the perspective direction.

    I searched for Ti devices(Precision ADC).

    1. ADS7863A  4Ch,  2000kSPS, 12bit ,  SPI ,          SAR
    2. THS1206    4Ch,   6000kSPS, 12bit,   Parallel,    Pipeline
    3. ADS8363    4Ch,  1000kSPS, 16bit ,  SPI ,          SAR
    4. ADS8168    8Ch , 1000kSPS, 16bit ,  SPI,           SAR

    Q1> Is it possible to convert ADC with ADC input frequency from 10Mhz to 100Mhz below?

    Q2> Please advise what to consider about the problem.

    Best Regards,
    Jame, Shin

  • In reply to Jame shin:

    Hello Jaime,

    Precision ADCs are normally not meant for undersampling applications and the analog bandwidth is usually not too far outside of the sampling frequency.  Therefore, the devices you're looking at in the last thread will not be able to undersample a 10MHz - 100MHz signal.

    Regards,
    Collin Wells
    Precision ADC Applications

  • In reply to Collin Wells:

    Hello Collin,

    Thank you for the reply.

    I understand what you say, but please answer the question below.

    Collin _A> Precision ADCs…normally not meant...bandwidth is usually not too far outside of the sampling frequency. 

    Q1> For THS1206 (Precision ADC), the analog input specification is specified in the differential (typ) 96Mhz, single-end (typ)54Mhz data sheet.

           What is the bandwidth of THS1206 device?

    Q2> Please suggest a device that can convert 10Mhz ~ 100Mhz signal to ADC from Precision ADCs device.

    Q3> If the question in Q2> is not answered, please suggest a device to solve.

    Best Regards,
    Jame, Shin

  • In reply to Jame shin:

    Hello Jamie,

    1.)  The THS1206 is on the high end of what's considered a Precision ADC by speed, but by application and operation it's used more like the higher-speed ADCs we'd mentioned before.  It does in fact have an analog bandwidth that's higher than the sampling rate and can be used for undersampling.

    2.)  Does the THS1206 meet your requirements? What you found in the datasheet is correct.

    Regards,
    Collin Wells
    Precision ADC Applications

  • In reply to Collin Wells:

    Hello Collin,

    Thank you for the reply.

    To help my understanding, please answer the question number “Qn> “In response” “An>”.

    Collin_1) The THS1206 .. . It does in fact .. analog bandwidth that's higher than the sampling rate and can ..  undersampling.

           Q1> I am worried that the precision ADC device is not wide bandwidth.

                   What is the actual THS1206 analog bandwidth range?  (single-end & differential)

    Collin_2) Does the THS1206 meet your requirements?

                   A1> No, I need ADC bit 14bit Up to 16bit and Sample rate 1Msps Up to 5Msps (Simultaneous Sampling).

    Q2> Please suggest the ADC device recommended for the application.

    Best Regards,
    Jame, Shin