https://devzone.nordicsemi.com/f/nordic-q-a/19263/nrf52840-i2s-consumptionWhat is the most energy efficient microphone input method, PCM via I2S or PDM. Does the SoC have a special HW handling of the PDM format for converting to PCM? Does the filtering of the 1 bit conversion compete with other processes on the SoC for resourcesen-USTelligent Community 13Wed, 01 Feb 2017 15:35:44 GMThttps://devzone.nordicsemi.com/thread/74637?ContentTypeID=1Wed, 01 Feb 2017 15:35:44 GMT137ad170-7792-4731-bb38-c0d22fbe4515:e189184d-db0c-4c5d-ba70-114fae402a96Ole Bauck<p>Also see this post: <a href="https://devzone.nordicsemi.com/question/112256/nrf52-microphone-saadc-pdm-or-i2s/">devzone.nordicsemi.com/.../</a></p><div style="clear:both;"></div>https://devzone.nordicsemi.com/thread/74636?ContentTypeID=1Wed, 01 Feb 2017 15:31:59 GMT137ad170-7792-4731-bb38-c0d22fbe4515:125453ec-2097-455d-b5d6-e5e58d269266Ole Bauck<p>Hi,</p> <p>The I2S current consumption is not specified in the product specification, but is about the same as PDM.</p> <p>The PDM has hardware decimation filters to convert the incoming data stream into PCM audio samples, see <a href="http://infocenter.nordicsemi.com/topic/com.nordic.infocenter.nrf52840.ps/pdm.html?cp=2_1_0_41_2#concept_tn3_xt2_yr">here</a>. This does not compete with other processes on the SoC.</p> <p>I would use PDM over I2S as the I2S on nRF52 has some erratas, see <a href="http://infocenter.nordicsemi.com/topic/com.nordic.infocenter.nrf52840.EngA.errata/err_840_new.html?cp=2_1_1_0_1">here</a>.</p> <p>Ole</p><div style="clear:both;"></div>