Graphics, sound and multimedia • I2S microphone change (Syntiant SPH0645LM4H-B to TDK InvenSense MMICT5848-00-012)

I have been using Syntiant SPH0645LM4H-B I2S microphone in my projects, but this device is now obsolete. I was also always unhappy with the AOP of SPH0645LM4H-B.

I would like to make TDK InvenSense MMICT5848-00-012 work with the Pi. This mic has 2 issues with the Pi 1) works at 1.8v and 2) is 32-bit sample.

I build a 1.8v rail (Diodes Incorporated AP2112K-1.8TRG1) and use Texas Instruments TXU0304PWR logic level translator mapping clock and word select thru the forward pins (A1->B1Y, A2->B2Y) and the data thru the backward pins (A4Y<-B4) with VCCA at 3.3v and VCCB 1.8v.

I do not have an oscilloscope so can only check voltages. A1 & A2 are 1.65V and B1Y and B2Y are 0.9v which is what I expect at 50% duty cycle. A4Y & B4 are 0v.

I get no sound from “arecord -D plughw:2,0 -c 1 -r 48000 -f S24_LE test.wav” and no voltage on A4Y & B4 even when sound is present.

I am not using the Acoustic Activity Detect (AAD) mode of the TDK mic, so the WAKE and THSEL pins are not connected.


Any ideas on what I am doing wrong or what I should try?

Thanks

Statistics: Posted by wkeeling — Thu Sep 03, 2026 1:28 am — Replies 1 — Views 25

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