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AD9690-500 as a replacement for AD9652

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Product Number: AD9690

Hi,

I previously designed with AD9652-310. In the next design, the AD9690-500 is considered as an alternative to change the LVDS interface of this AD9652-310 to JESD204B.

We previously received an RF input of 100 MHz bandwidth with 180 MHz as the center and the sampling rate was approximately 250 MSPS.

However, the datasheet of AD9690 indicates that the minimum sampling clock is 300MSPS. So I wonder if it is possible to receive 500MHz and sample at 250MSPS using the internal divider? Or is it not possible to use the same sample rate (about 250MSPS) as the existing device ?

In other words, I am looking for a device that has the JESD204B interface and is most similar to the AD9652 in performance. And I am looking for an ADC that can use the same sample rate (250MSPS) and bandwidth of 125-235 MHz as an analog input so that the existing design can be reused. If AD9690 cannot be a replacement, can you recommend me another best device?

Thanks.

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  • Peevee,

    Thank you for your suggestion.

    I'm sorry I didn't mention exactly that the AD9652 design uses a variable sampling clock (240~ 260 MSPS) and its maximum sampling rate is 260MSPS.

    The two ADCs you suggested seem to have many advantages. However, they only support 250MSPS, so it doesn't seem to satisfy the specifications I want to use.

    Could you please suggest again with the following sampling rate?

    Sampling rate: 240 ~ 260MSPS

    Analog Input: 125~235 MHz (Carrier Freq: 180MHz) 

    And I wonder if I can make the same condition as the AD9652 by adjusting the sampling rate to 520MSPS (260MSPS x 2) and the decimation ratio of the internal filter to 2 using the AD9690-1000.

    Thanks,

  • Hi seung-gon,

    Thank you for clarifying.

    And I wonder if I can make the same condition as the AD9652 by adjusting the sampling rate to 520MSPS (260MSPS x 2) and the decimation ratio of the internal filter to 2 using the AD9690-1000.

    Your understanding is correct, operating in AD9690 in DDC mode can achieve your desired sampling rate. 

    You may refer to these articles for the discussion about the DDC:
    What’s Up With Digital Downconverters—Part 1 | Analog Devices
    What’s Up With Digital Downconverters Part 2 | Analog Devices

    This article features AD9680 family's DDC where AD9690 belongs.

    You may also explore the AD9680 using the virtual eval tool. This is also discussed in the article I shared.

    Here is the link for the virtual eval tool: Virtual Eval | Analog Devices

    Let us know if you have further questions regarding this.

    Best regards,
    Peevee