FAQ: Can a digital microphone's PDM output be directly connected to an I2S input?

A PDM output microphone, such as the ADMP421 or ADMP521, cannot directly interface to an I²S port. Theses microphones should be connected to the PDM input on codecs such as the ADAU1361 and ADAU1761. The ADMP441 MEMS microphone has an I²S output that can be connected directly to a processor or codec's I²S input port.

We have a few Circuits from the Lab that explain connections between digital microphones and other devices:

CN0078: Digital MEMS Microphone Simple Interface to a SigmaDSP Audio Codec (ADMP421, ADMP521, ADAU1361, ADAU1761)

CN0208: High Performance MEMS Digital Microphone's Simple Interface to SigmaDSP Audio Processor (ADMP441, ADAU1446)

CN0266: High Performance Digital MEMS Microphone Standard Digital Audio Interface to Blackfin DSP (ADMP441, ADSP-BF527 Blackfin)