AD8333 + PCM4220


I have the next  hardware configuration:

AD8331 + AD8333 + AD8021 + Buffer + ADC (PCM4220).

Buffer schematic:

My device must  works with input signal level (~  - 120dBm).

1) Tell me please, buffer  hardware configuration is optimal for matching AD8021 and PCM4220 ?

2) Сan I get sensitivity near -120 dBm with using AD8333 demodulator ?

I am hope for your help.


  • 0
    •  Analog Employees 
    on Sep 17, 2015 10:12 PM

    Hello Alex,

    Thanks for your email re the AD8333. My response to your questions 1 and 2 above:

    1) As I look at your two circuits it would seem that they're set up in a cancellation mode, that is to say each of the two amplifiers comprising the upper and lower pairs are inverted with respect to one another and summed at their outputs to null one another at the PCM4220 inputs. I must admit I don't recognize practical application of the  the circuit, and am not much of an expert in extrapolating what you are trying to achieve here.

    2.) As for the -120dBm signal, the bandwidth of your filters are of such a magnitude that I doubt you'll see much other than wideband noise at the output. However we device people are more attuned to performance nuances of our products and the applications to which they are dedicated. In this case, that would mean Doppler vs. digital beam forming where the AD8333 operates as part of a diversity receiver. Assuming you mean to use a single channel in a conventional receiver configuration, I don't think the AD8333 is what you're looking for. That said, I might suggest you search out conventional I/Q demodulators that may fit your purpose. Then be sure you have enough gain with a low-noise amplifier to achieve the intended results.

    Good luck,


  • Hello jstaley,

    Thanks for your answer.

    1) My two circuits represent ADC Driver With Single-Ended Input to Differential Output for (I) and (Q) channel respectively.

    2) It should be a SDR HF receiver (1.6MHz - 30MHz)  with   AM, FM and SSB  demodulation. I don't find other  I/Q demodulators which works in band   (1.6MHz - 30MHz) and have the nice  phase accuracy  and  amplitude balance.


  • 0
    •  Analog Employees 
    on Aug 2, 2018 3:11 PM
    This question has been assumed as answered either offline via email or with a multi-part answer. This question has now been closed out. If you have an inquiry related to this topic please post a new question in the applicable product forum.

    Thank you,
    EZ Admin