AMC1302EVM: Noise on AMC1302EVM ?

Hi Riko,

I think that you're seeing noise from the 5M resistor. Adding an RC filter to the input of the device will help.

The AMC1302EVM has placeholder's for such a filter. Resistors R1 and R2 are 0ohm resistors and C8, C4, C5, are DNP, so currently there is no filter in place. You can easily install components to add your own filter.

For design of the RC filter, please refer to section 5 of the precision labs series: training.ti.com/ti-precision-labs-adcs

Hi Riko,

Yes, you can use a low pass passive filter. What frequency is the noise that you are seeing?

From what I understand about your measurement, the fundamental signal that you are measuring is 60Hz (240VAC). If you use a cutoff frequency of 60Hz then the fundamental signal will see attenuation as well as the noise. I would increase the cutoff frequency to at least 600Hz so that the fundamental signal sees minimal attenuation.

DNP means "do not populate" or "do not install".

Hi Riko,

Ceramic is fine. C0G or X7R.

For design of the RC filter, please refer to section 5 of the precision labs series: training.ti.com/ti-precision-labs-adcs

A resistor value of 10k will be too large. The input impedance of the AMC1302 is less than 30kOhm. Voltage sensing applications typically use a high input impedance device such as the AMC1311 since the input stage is essentially a voltage division circuit. You may want to consider a device with a higher input impedance.