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Casperdroid5 , 03-06-2026, 05:06 PM

I have a design where I need to measure current of 2*48V 6A (12A total). The power (low side) will be switched using pwm in a frequency range of somewhere between 0Hz - 3kHz.


I have not finished routing the ICs.

Will I have EMI problems interfering with the current sensors output? If so please explain your thought proces. The current sensor ICs ACS71240LLCBTR (soic-8 package) have an analog output.

QDrives , 03-06-2026, 07:59 PM

Your EMI problem will be an EMI problem of the original signal.
How much your measurement is affected by it, will be determined by that signal.

Casperdroid5 , 03-07-2026, 11:41 PM

I'm sorry, I'm not following. Do you mean that the pwm Frequency is the EMI problem frequency? So that pwm will effect the signal (analog output of IC)

QDrives , 03-08-2026, 01:45 AM

Your question was "*Will I have EMI problems interfering with the current sensors output?*".
If that is the case, then your PWM signal is the cause already (not the IC).
With good layout and filtering you should be able to minimize the effect.

Casperdroid5 , 03-09-2026, 08:38 AM

Got it. So by using a 156 Hz RC filter on the output of the current IC, could already be beneficial in that case I'm thinking.

QDrives , 03-12-2026, 10:26 PM

156Hz may be to low and may not be needed at all.
But keeping space to add them if needed is a good idea.