i have bought an ADL5910 peak/envelope eval board to get peak voltages with peak period 1.67 seconds.
basically, the element i am trying to measure has a peak voltage of around 0.4 to 40 volts which occurs every 1.67 seconds. All I want to do is get the peak voltage from each pulse and output those values to a microprocessor.
I have been trying to use the data sheet which describes the 5910 but it doesn't seem to indicate where to measure the output - I tried Q but it seems this is just the flip-flop as it outputs 0 or 1 only. If i'm running the signal into Rfin_SW, do I measure output peak values at Rfout_SW? Also, it seems that the board has to be reset manually from outside after each peak is detected - is that right?
Any help much appreciated as, clearly, I am a newbie on this stuff.
The output voltage at pin 3 (VCAL) is the envelope detector voltage. It is also corresponding to the RF input power from RFIN pin.
The "Evaluation Board" section on data sheet page 19 talks more about the RFIN_SW and RFOUT_SW connectors. Table 6 starting on page 20 lists out each function of the ADL5910 evaluation board.
The Eval. Board has "S1 Switch" for manually reset the flip-flop.
Hope these can help.
One other question is, with the peaks detecting properly, I assume the output would be sensed at RFout_SW and if so, is it a digital or analog output?
Thanks a lot for your help on this man - much appreciated - as you can see, I' m a mechanical engineer, not electrical ;-)
If you do not have input RF signal, the ADL5910 device will not work with your application.
Sorry John but I'm really not quite sure what you mean by not having an RF input signal? I do have one, as described in previous posts including images in the early posts. Perhaps I am confusing this with some other separate input signal? Explanation much appreciated. Cheers, Nick
Reading through the above correspondence, it's not clear from your oscilloscope photo if there is an RF carrier wave present, or not. A much higher resolution photo is necessary. Offhand, so far, it looks to me like you would be better off with the diode and op-amp peak-detector circuit, like you posted the web link for, above. I might add that you can use our LTspice to help simulate the RC values to give favorable attack and decay times for the circuit that will work best with your MCU.