AD8232 Leads Off Detection Question


I am using the AD8232 in a Bluetooth Low Energy Heart Rate Monitor Application.  I am currently in the process of hardware verification of the prototype boards.  I am currently using two resting ECG Electrodes attached to myself to monitor the heartbeat.  I am using the AC Leads Off Detection Mode.  When I connect the ECG Electrodes to myself, I was expecting the LOD+ signal on the AD8232 to transition from the Logic High State to the Logic Low State.  What I am observing is the LOD+ signal toggling at approximately 60 Hz.  Is this the response I should be seeing from the LOD+ signal?  If not, why is it toggling instead of transitioning to Logic Low State and then remain at this state until an Electrode is removed?

Your help would be greatly appreciated.



  • Gustavo,

    Thanks for your detailed reply.  We will keep this in mind as we continue with the hardware verification effort of our development platform.

    One additional question I have has to do with the proper test method to use to verify the AD8232 functionality on our development platform.  Currently we have an Agilent Arbitrary Waveform Generator that we are using to generate a cardiac waveform into the instrumentation amplifier of the AD8232.  We are then verifying this signal at the output of the AD8232.  In addition, we are verifying that our A-to-D converter is able to detect the cardiac waveform.  Eventually we would like to verify the functionality of the AD8232 on a human.  Could you please provide recommendations on the proper test techniques to use to achieve this goal?  What test techniques does Analog Devices use to verify this functionality?

    We are also working with a company to develop a strap with electrodes that will be worn around the chest to monitor the persons heart rate.  Any recommendations on the electrical characteristics to specify for the electrodes that will be of the chest strap?  Any help you could provide in this area would also be greatly appreciated.

  • Hello, how did you solve this problem, thank you.

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