ADA2200 Question

Dear Sir/Madam,
I use ADA2200 for testing in a project , and  need to measure the sensor input signal 's amplitude and phase .
1 . B ecause input singla could not guarantee constant within a short time , I want to use 2 ADA2200 to realize above function , one is for phase detection , another piece is for orthogonal   detection, I do not know whether it is avail able ?
2 . Because it is best to use sine excitation for the sensor excitation , RCLK goes through 3-order active low - pass filter into sinusoidal ( frequencies 4KHz ) , is this solution available ?
Thanks.
Parents
  • Dear brianharrington,

             I am a Chinese engineer, please forgive me for my bad English. I am currently developing luminescent dissolved oxygen (LDO), which is achieved by detecting the phase shift between fluorescence and excitation light, the phase shift Is related to the concentration of dissolved oxygen.

    As the phase shift is small, the dissolved oxygen concentration changes from 0% to 100% when the phase shift is only about 10 °@10KHz, so in order to ensure a certain degree of accuracy I use the relevant detection method, using a single spectral excitation sine wave excitation blue LED light source, and then photocell Receiving fluorescence emitted by fluorescent materials, through the AD8615 I / V conversion, and then by the BPF after the relevant part of the input test for the relevant detection.
            As the ADA2200 phase detection accuracy is 0.0093 °, I would like to use ADA2200.However, RCLK of ADA2200 is square wave instead of sinusoidal. If RCLK is used to modulate LED, then the signal received by photoelectric tube after I / V conversion of AD8615, AD8615 output signal should be the same frequency as RCLK, Contains the fundamental frequency, also contains odd times the fundamental frequency of the harmonics, so that the ADA2200 phase-locked output signal after the conversion to phase there will be errors, right?
         One thing I can not confirm, this AD8615 output signal through the ADA2200 IIR filter will become the same frequency with the RLCK sinusoidal signal, if so then ADA2200 in my system to detect the accuracy of the phase can be accurate.
         The problem is bothering me, and I very much hope that you will give me some advice!
         China's New Year has just passed,  I hope you can share the joy of our holiday! Blessing of the Chinese New Year!
         Wishing you prosperity!
Reply
  • Dear brianharrington,

             I am a Chinese engineer, please forgive me for my bad English. I am currently developing luminescent dissolved oxygen (LDO), which is achieved by detecting the phase shift between fluorescence and excitation light, the phase shift Is related to the concentration of dissolved oxygen.

    As the phase shift is small, the dissolved oxygen concentration changes from 0% to 100% when the phase shift is only about 10 °@10KHz, so in order to ensure a certain degree of accuracy I use the relevant detection method, using a single spectral excitation sine wave excitation blue LED light source, and then photocell Receiving fluorescence emitted by fluorescent materials, through the AD8615 I / V conversion, and then by the BPF after the relevant part of the input test for the relevant detection.
            As the ADA2200 phase detection accuracy is 0.0093 °, I would like to use ADA2200.However, RCLK of ADA2200 is square wave instead of sinusoidal. If RCLK is used to modulate LED, then the signal received by photoelectric tube after I / V conversion of AD8615, AD8615 output signal should be the same frequency as RCLK, Contains the fundamental frequency, also contains odd times the fundamental frequency of the harmonics, so that the ADA2200 phase-locked output signal after the conversion to phase there will be errors, right?
         One thing I can not confirm, this AD8615 output signal through the ADA2200 IIR filter will become the same frequency with the RLCK sinusoidal signal, if so then ADA2200 in my system to detect the accuracy of the phase can be accurate.
         The problem is bothering me, and I very much hope that you will give me some advice!
         China's New Year has just passed,  I hope you can share the joy of our holiday! Blessing of the Chinese New Year!
         Wishing you prosperity!
Children
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