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About Note 5 description of LTC5582

Hello

Note 5 on page 4 of the LTC5582 data sheet has the following:

Would you please disclose this detailed information?

I would be grateful if you could reply.

Best Regards,
Knj

Parents
  • Hello Knj,

    In years gone by, some of our customers used LTC5582 up at higher RF input frequency, beyond the specified 10GHz max. The reason is, there were no other higher frequency parts available at the time, and the LTC5582 performance up around 12 GHz was still good enough for the application.   If you have specific RF frequency or frequency range in mind, please specify. In the final design, the RF input matching should be customized for the end application's PCB. 

    Now in 2021, Analog Devices has more detectors to choose from, so for higher RF frequency, it's better to choose a RF detector already specified to cover the desired RF frequency range. See for example the LTC5596 rms detector, HMC1094 log detector, or ADL6010 Schottky peak detector for examples.  -Bruce H. 

Reply
  • Hello Knj,

    In years gone by, some of our customers used LTC5582 up at higher RF input frequency, beyond the specified 10GHz max. The reason is, there were no other higher frequency parts available at the time, and the LTC5582 performance up around 12 GHz was still good enough for the application.   If you have specific RF frequency or frequency range in mind, please specify. In the final design, the RF input matching should be customized for the end application's PCB. 

    Now in 2021, Analog Devices has more detectors to choose from, so for higher RF frequency, it's better to choose a RF detector already specified to cover the desired RF frequency range. See for example the LTC5596 rms detector, HMC1094 log detector, or ADL6010 Schottky peak detector for examples.  -Bruce H. 

Children
  • Thank you for your reply.

    We would like to use the frequency range up to 10.5GHz.
    Certainly the LTC5596 covers 10.5GHz, but it's over-engineered.
    If you have any detailed information, please disclose it.

    I would appreciate it if you could reply.

    Best Regards,
    Knj

  • Hello Knj,

    Take a look at the figure posted here. It is a design for 8 to 12 GHz band. Sorry, no schematic available, but see the figure for circuit notes: C4= 0.3pF, C5 removed. These are the modifications to the factory demo board. Kindly note, when transfering the design to a different PCB, actual values for C4 and C5 may need to be slightly revised.

    The figure is showing input matching in the top trace, and detector response in DC Volts on the bottom trace. Notice how response is lower up at these higher frequencies, and dynamic range is going to be degraded, compared to operation at lower frequencies. Depending on the application, this level of performance may or may not be acceptable.   -Bruce H.