Hi all,
I am currently experimenting with an EMG circuit. The instrumentation amplifier being used for this circuit is the AD8237.
The following snapshots show what kind of line frequency interference is being encountered with this circuit.
1) Snapshot below shows the interference level whenever I am not making contact with anything:
2) Snapshot below shows the interference level whenever I touch the surface of my laptop (plugged to the mains supply) - 50Hz interference:
3) Snapshot below shows the interference level whenever touch the floor barefooted - 50Hz interference:
Can someone please advise what kind of measures I can take to eliminate/reduce this interference?
I can introduce a notch filter, but since the EMG frequency is in the range of 10-300Hz, introducing a notch filter will also attenuate the EMG signal.
In the datasheet, it is mentioned that if additional filtering is required, one can introduce a filter at the inputs of the IA (snapshot below). Will this help in reducing line frequency interference and will it drastically affect the CMRR of the IA?
Any kind of help would be highly appreciated.
I am currently experimenting with an EMG circuit. The instrumentation amplifier being used for this circuit is the AD8237.
The following snapshots show what kind of line frequency interference is being encountered with this circuit.
1) Snapshot below shows the interference level whenever I am not making contact with anything:
2) Snapshot below shows the interference level whenever I touch the surface of my laptop (plugged to the mains supply) - 50Hz interference:
3) Snapshot below shows the interference level whenever touch the floor barefooted - 50Hz interference:
Can someone please advise what kind of measures I can take to eliminate/reduce this interference?
I can introduce a notch filter, but since the EMG frequency is in the range of 10-300Hz, introducing a notch filter will also attenuate the EMG signal.
In the datasheet, it is mentioned that if additional filtering is required, one can introduce a filter at the inputs of the IA (snapshot below). Will this help in reducing line frequency interference and will it drastically affect the CMRR of the IA?
Any kind of help would be highly appreciated.