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LMH2121: Envelope Detector Referance Design?

Pete Sampson
Intellectual 440 points
Part Number: LMH2121


Tool/software:

Are there any referance design or apps notes for envelope detectors?

I'm looking to make an envelope detector for a 500kHz signal. Ideally it would be a full wave envelope detector but a half wave would be better than nothing. The LMH2121 is for 100M to 3GHZ and much faster and power hungry than I need. The diode detector it referances in the datasheet as an example won't pass small signals until they get over the forward drop of the diode so that won't work. 

  • 0
    TI__Expert 4550 points

    Hi Pete,

       Is the modulation bandwidth 500KHz?  Can you help me understand your signal type?

    Regards,

    Hruday

  • 0 in reply to Hruday Kumar Mudireddy
    Intellectual 440 points

    Thanks Hruday, happy to provide more information. The signal being received is centered at 500khz. The pulse length is 10-20uS so bandwidth is +-50kHz (100kHz max). The signal will be either a PWM or a sine wave but either way I want to track the amplitude vs. time, rather than needing to demodulate or process a 500 kHz sine wave with a micro.Since this is a battery operate system low power is key.

    The signal is the return signal for a sonar system but I don’t want this to be moved to the sonar section where the chips already have integrated envelope detectors. I want to build my own external envelope detector using TI parts.

  • 0 in reply to Pete Sampson
    Intellectual 440 points

    Bumping this up again. If I can provide additional info please let me know.

  • +1 in reply to Pete Sampson
    TI__Expert 4550 points

    Hi Pete,

       Apologies for the delayed response. I see you want to detect 500kHz signal with detector response time << 10uS. Currently TI do not offer any power detector with min frequency < 50MHz. unfortunately, I did not find any suitable parts from TI to implement this discretely.

    Regards,

    Hruday