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AD5940 Recommended for New Designs
The AD5940 and AD5941 are high precision, low power analog front ends (AFEs) designed for portable applications that require high precision, electrochemical...
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AD5940 and 60601-1

PaulRimmer

on Nov 28, 2023

Category: Hardware

Product Number: AD5940

Hi,

I am working on a bioimpedance application and have been using the AD5940 eval kit. In one of the application notes, it ahs the following.

I have been looking through the 60601 standard as it relates to this application and I cannot find a reference for where the max allowable ac current as a function of frequency is stated. Does anybody know where the values in the application note come from. I admittedly get very easily lost in reading the standard, but the closest thing I could find are the references to Patient Auxiliary Currents, which appear to be limited to 100uA in normal operation and are not frequency dependent.

Any steer in the right directions would be appreciated.

0 mark.ramos

on Nov 29, 2023 11:03 AM
Hi Paul,

We are looking into this.

The person who worked on this application note has moved to a different group so we need to consult him before getting back with an answer.

For now, I just want to highlight that the application boards for AD5940 should be used for evaluation purposes only and should not be connected to a body for measurement.

regards,

Mark
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0 NathanT

on Nov 29, 2023 9:49 PM
Hi PaulRimmer ,

Akila and mark.ramos will look into this.

Regards,
Jo
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0 mark.ramos

on Nov 30, 2023 4:10 AM
Hi Paul,

This information came from IEC60601. There is a figure inside the IEC60601-1 document that shows that current can be increased as frequency increases.

regards,

Mark
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0 PaulRimmer
on Nov 30, 2023 5:42 AM in reply to mark.ramos
Thanks is the equation inferred from the frequency response of the recommended measurement setup as shown below? We cannot find any other reference in 60601-1, do you have the specific clause we can look up?
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0 mark.ramos

on Nov 30, 2023 6:01 AM in reply to PaulRimmer
Hi PaulRimmer,

The images you have above are the ones they used to get the maximum current at 50kHz and 60kHz. Sorry, but I was not able to get more information other than this.

regards,

Mark
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0 PaulRimmer
on Nov 30, 2023 6:06 AM in reply to mark.ramos
thank you.
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