https://devzone.nordicsemi.com/f/nordic-q-a/25483/analog-ground-on-nrf52832-chipHi, I am designing a PCB which consists of an analog circuitry (microphone + analog front end) and the nrf52832 chip. I am using inbuilt-ADC of this chip to sample the acoustic signal. The problem is that the PCB outputs a lot of noise than the expecteden-USTelligent Community 13Wed, 27 Sep 2017 10:44:16 GMThttps://devzone.nordicsemi.com/thread/100421?ContentTypeID=1Wed, 27 Sep 2017 10:44:16 GMT137ad170-7792-4731-bb38-c0d22fbe4515:d8eef852-7fb2-4c9a-b783-730eaf1a85d3J&#248;rgen Holmefjord<p>Hi,</p> <p>There is no dedicated analog ground on the nRF52832. You can see all pins and their functionality on <a href="http://infocenter.nordicsemi.com/topic/com.nordic.infocenter.nrf52832.ps.v1.1/pin.html?cp=2_1_0_3#pin_assign">this page</a>. Note this comment from the <a href="http://infocenter.nordicsemi.com/topic/com.nordic.infocenter.nrf52832.ps.v1.1/saadc.html?cp=2_1_0_36_1#saadc_overview">SAADC documentation</a>:</p> <blockquote> <p>The assumption in single-ended mode is that the internal ground of the ADC is the same as the external ground that the measured voltage is referred to. The ADC is thus sensitive to ground bounce on the PCB in single-ended mode. If this is a concern we recommend using differential measurement.</p> </blockquote> <p>If you are using single ended mode, you can try switching to differential measurement. Another method to reduce noise is to <a href="http://infocenter.nordicsemi.com/topic/com.nordic.infocenter.nrf52832.ps.v1.1/saadc.html?cp=2_1_0_36_4_2#saadc_operationmodes_oversample">enable oversampling</a>.</p> <p>Best regards,</p> <p>Jørgen</p><div style="clear:both;"></div>