Dialectical Data
~/workshop $ cat ./inventory/inmp441-i2s-mems-mic/README.md

INMP441 I2S MEMS Microphone Module (EC Buying, 5pcs)

category
Sensor
qty
5
status
owned / untested
maker
TDK InvenSense (INMP441 die); breakout board assembled/resold by EC Buying
INMP441 I2S MEMS Microphone Module (EC Buying, 5pcs)

Overview

A high-performance, low-power, omnidirectional MEMS microphone with a digital I2S output. It integrates the MEMS sensing element, signal conditioning, a 24-bit ADC, and an anti-aliasing filter on one die, so it hands a microcontroller clean 24-bit digital audio directly over I2S — no analog front-end or separate ADC needed. Common in voice-capture, wake-word, and audio-recording projects (e.g. ESP32-based recorders).

Key specs

  • Operating voltage: 1.8–3.3V DC
  • Logic level: 1.8–3.3V (matches supply)
  • Current draw: ~1.4mA average
  • Interfaces: I2S (digital audio output — not I2C, despite the visual similarity)
  • Frequency response: 60Hz–15kHz
  • Sensitivity: ~-26dBFS
  • SNR: 61dB(A)

Pinout

Pin Function
VDD Power (1.8–3.3V)
GND Ground
L/R Channel select — low = left channel, high = right channel
WS Word Select (I2S left/right clock)
SCK Serial clock (I2S bit clock)
SD Serial data output (I2S)

Wiring / typical usage

Power from 3.3V. Tie L/R to GND for the left channel (or 3.3V for right) — on a single-mic setup this just fixes which I2S slot the data lands in. Wire SCK/WS/SD to the host’s I2S peripheral pins. No pull-ups needed; the module drives SD directly and tri-states it when not its turn to speak (relevant if multiple INMP441s share a bus for stereo/array capture).

Code / libraries

  • ESP32 (Arduino/ESP-IDF): use the built-in driver/i2s.h (or ESP32-A2DP/I2S library) — INMP441 is the de facto standard test mic for ESP32 I2S examples.
  • CircuitPython/MicroPython: audiobusio.I2SIn (CircuitPython) has direct examples for this exact part.
  • Config notes: 24-bit samples in a 32-bit I2S frame is typical; sample rate commonly 16–44.1kHz for voice/audio capture.

Source material

  • Datasheet/specs: components101 INMP441 module page, Digi-Key INMP441 datasheet
  • Purchase link: Amazon, “EC Buying 5Pcs INMP441 Omnidirectional MEMS Microphone Module”
  • Product photo: /inventory/inmp441-i2s-mems-mic/product-photo.jpg — sourced from components101’s module photo (generic INMP441 breakout — same board layout/pin labels as the widely-resold version this listing ships; not confirmed pixel-identical to the exact EC Buying unit).

Verification

Pinout and specs verified against the TDK InvenSense INMP441 datasheet and components101's module writeup — high confidence for the chip itself. Board silkscreen/pin order on the specific EC Buying breakout not independently confirmed — check against the physical board before wiring.

Notes / gotchas

  • I2S, not I2C — easy to misread at a glance. No address, no SDA/SCL.
  • If building a stereo pair, tie one module’s L/R to GND and the other’s to VDD, and they’ll interleave into one I2S stream automatically.